├── .gitignore
├── LICENSE
├── README.md
├── crossed-example.png
├── sketchy-example.png
├── spiral-example.png
├── src
├── blackstripes
│ ├── __init__.py
│ ├── blackstripes_signature.h
│ ├── crossed-large.h
│ ├── crossed-xlarge.h
│ ├── crossed.c
│ ├── sketchy.c
│ └── spiral.c
├── cli
│ └── blackstripes
├── lib
│ ├── lodepng
│ │ ├── lodepng.c
│ │ └── lodepng.h
│ └── sketchy
│ │ ├── FSArray.c
│ │ ├── FSArray.h
│ │ ├── FSNumber.c
│ │ ├── FSNumber.h
│ │ ├── FSObject.c
│ │ ├── FSObject.h
│ │ ├── Point.c
│ │ ├── Point.h
│ │ ├── SketchyImage.c
│ │ ├── SketchyImage.h
│ │ └── bool.h
└── setup.py
└── test
├── ali.png
├── crossed-test.py
├── image.png
├── luxx_test.py
├── sketchy-test.py
└── spiral-test.py
/.gitignore:
--------------------------------------------------------------------------------
1 | # Byte-compiled / optimized / DLL files
2 | __pycache__/
3 | *.py[cod]
4 |
5 | # C extensions
6 | *.so
7 | *.o
8 |
9 | #macosx
10 | .DS_Store
11 |
12 |
13 | # Distribution / packaging
14 | .idea/
15 | .Python
16 | venv3/
17 | venv/
18 | env/
19 | src/build/
20 | develop-eggs/
21 | dist/
22 | downloads/
23 | eggs/
24 | .eggs/
25 | lib64/
26 | parts/
27 | sdist/
28 | var/
29 | *.egg-info/
30 | .installed.cfg
31 | *.egg
32 |
33 | # PyInstaller
34 | # Usually these files are written by a python script from a template
35 | # before PyInstaller builds the exe, so as to inject date/other infos into it.
36 | *.manifest
37 | *.spec
38 |
39 | # Installer logs
40 | pip-log.txt
41 | pip-delete-this-directory.txt
42 |
43 | # Unit test / coverage reports
44 | htmlcov/
45 | .tox/
46 | .coverage
47 | .coverage.*
48 | .cache
49 | nosetests.xml
50 | coverage.xml
51 | *,cover
52 |
53 | # Translations
54 | *.mo
55 | *.pot
56 |
57 | # Django stuff:
58 | *.log
59 |
60 | # Sphinx documentation
61 | docs/_build/
62 |
63 | # PyBuilder
64 | target/
65 |
--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
1 | The MIT License (MIT)
2 |
3 | Copyright (c) 2015 Johan ten Broeke
4 |
5 | Permission is hereby granted, free of charge, to any person obtaining a copy
6 | of this software and associated documentation files (the "Software"), to deal
7 | in the Software without restriction, including without limitation the rights
8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 |
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 |
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 |
23 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | # Blackstripes python extensions
2 | ### Your drawbot will like it!
3 |
4 | This is a python module written in c. It turns an png image into a svg line drawing. The output is very suitable for vsg capable drawbots. We use it every day on [blackstripes.nl](http://www.blackstripes.nl).
5 |
6 | This also comes with a command-line interface for using it, installed at the same time as the python module. Check `blackstripes --help` for detailed usage.
7 |
8 | ## How to use
9 |
10 | This module exposes 3 drawing styles.
11 |
12 | ### 1. Sketchy
13 |
14 | from blackstripes import sketchy
15 |
16 | sketchy.draw("ali.png", # input
17 | "ali_sketchy.svg", # output
18 | 1, # nibsize (line size in output svg)
19 | 100, # max line length
20 | "#000000", # line color
21 | 0.32, # scaling factor
22 | 1, # line size (internal line size for calculations)
23 | 540, 1021, 0.7 # signature transform tx, ty, scale
24 | )
25 |
26 | Using the CLI:
27 |
28 | blackstripes sketchy ali.png --output ali_sketchy.svg
29 |
30 |
31 | 
32 |
33 | ###### How does it work
34 |
35 | 1. Calculate the brightness of the input image.
36 | 2. Place the pen at pixel 0,0.
37 | 3. Get a random line length between 10 and the max segment length.
38 | 4. Evaluate 360 lines by making a 360 degree sweep with the selected line length.
39 | 5. Get the line covering the largest average darkness in the input image.
40 | 6. Draw this line white in the input image.
41 | 7. Draw this line black in the ouput image.
42 | 8. Calculate the brightness of the output image.
43 | 9. Repeat from step 2 until the brightness of the output image is equal to the inpute image.
44 |
45 |
46 | ### 2. Crossed
47 |
48 | from blackstripes import crossed
49 |
50 | crossed.draw("ali.png", # input
51 | "ali_crossed.svg", # output
52 | 2.0, # nibsize (line size in output svg)
53 | "#2200aa", # line color
54 | 0.32, # scaling factor
55 | 200, 146, 110, 56, # levels
56 | 2, # type
57 | 540,1021,0.7 # signature transform
58 | )
59 |
60 |
61 | Using the CLI:
62 |
63 | blackstripes crossed ali.png --output ali_sketchy.svg
64 |
65 |
66 | 
67 |
68 |
69 | ### 3. Spiral
70 |
71 | from blackstripes import spiral
72 |
73 | spiral.draw("ali.png", # input
74 | "ali_spiral.svg", # output
75 | 2.0 , # nibsize (line size in output svg)
76 | "#aa0000", # line color
77 | 0.32, # scaling factor
78 | 180, 108, 180, 108, # levels
79 | 2, # linespacing
80 | 540,1021,0.7 # signature transform
81 | )
82 |
83 |
84 | Using the CLI:
85 |
86 | blackstripes spiral ali.png --output ali_sketchy.svg
87 |
88 |
89 | 
90 |
91 |
92 | ## How to build
93 |
94 | (This module is tested with python 2.7 and python 3.4 on mac-osx and linux, but it will probably work on most platforms.)
95 |
96 | 1. Clone this repo
97 | 2. navigate to the src folder
98 | 3. `python setup.py build`
99 | 4. `python setup.py install`
100 | 5. navigate to the test folder
101 | 6. `python sketchy-test.py`
102 | 7. `python crossed-test.py`
103 | 8. `python spiral-test.py`
104 |
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/crossed-example.png:
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https://raw.githubusercontent.com/fullscreennl/blackstripes-python-extensions/366d3899b79daad5b6c5332a0ec63201374e46e4/crossed-example.png
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/sketchy-example.png:
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/spiral-example.png:
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https://raw.githubusercontent.com/fullscreennl/blackstripes-python-extensions/366d3899b79daad5b6c5332a0ec63201374e46e4/spiral-example.png
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/src/blackstripes/__init__.py:
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https://raw.githubusercontent.com/fullscreennl/blackstripes-python-extensions/366d3899b79daad5b6c5332a0ec63201374e46e4/src/blackstripes/__init__.py
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/src/blackstripes/blackstripes_signature.h:
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1 | static char signature[] ="";
2 |
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/src/blackstripes/crossed.c:
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1 | #include
2 | #include "Python.h"
3 | #include "../lib/sketchy/SketchyImage.h"
4 | #include "../lib/sketchy/Point.h"
5 | #include "crossed-large.h"
6 | #include "crossed-xlarge.h"
7 |
8 | #include "blackstripes_signature.h"
9 | //char *signature = "\n";
10 |
11 | static char module_docstring[] = "This module provides a blackstripes crossed png to svg conversion";
12 | static char draw_docstring[] = "Make a svg blackstripes classic of the png";
13 |
14 | static char svg_formatstring[] = "\
15 | \
16 | \n", sig);
174 | }
175 | fclose(svgFile);
176 | SketchyImage_release(im);
177 |
178 | char rsvgCommand[200];
179 | int rsvg_command_status = sprintf(rsvgCommand, "rsvg-convert -a -w 1000 %s -o %s.png --background-color '#ffffff'", output_filename, output_filename);
180 | if(rsvg_command_status){
181 | system(rsvgCommand);
182 | }
183 |
184 | }
185 |
186 | static PyObject *crossed_draw(PyObject *self, PyObject *args){
187 | const char *inputpng = "";
188 | const char *filename = "";
189 | const char *color = "";
190 | float nibsize = 1;
191 | float scale = 1.0;
192 | int level0 = 1;
193 | int level1 = 1;
194 | int level2 = 1;
195 | int level3 = 1;
196 | int type = 1;
197 | float sigTransX = 0.0;
198 | float sigTransY = 0.0;
199 | float sigScale = 1.0;
200 | if (!PyArg_ParseTuple(args, "ssfsfiiiiifff", &inputpng, &filename, &nibsize , &color, &scale, &level0, &level1, &level2, &level3, &type, &sigTransX, &sigTransY, &sigScale)){
201 | return NULL;
202 | }
203 |
204 | decodePNG(inputpng, filename, nibsize, color, scale, level0, level1, level2, level3, type, sigTransX, sigTransY, sigScale);
205 |
206 | PyObject *ret = Py_BuildValue("i", 0);
207 | return ret;
208 | }
209 |
--------------------------------------------------------------------------------
/src/blackstripes/sketchy.c:
--------------------------------------------------------------------------------
1 | #include "Python.h"
2 | #include "../lib/sketchy/SketchyImage.h"
3 | #include "../lib/sketchy/Point.h"
4 | #include "blackstripes_signature.h"
5 |
6 | static char module_docstring[] = "This module provides a sketchy png to svg conversion";
7 | static char sketch_docstring[] = "Make a svg sketch of the png";
8 |
9 | static char svg_formatstring[] = "\
10 | \
11 | \n", color, nibsize, sig);
113 | }
114 | fclose(svgFile);
115 |
116 | //SketchyImage_saveAsPNG(im,output_filename);
117 | //SketchyImage_saveStateAsPNG(im,"state.png");
118 |
119 | SketchyImage_release(im);
120 |
121 | char rsvgCommand[200];
122 | int rsvg_command_status = sprintf(rsvgCommand, "rsvg-convert -a -w 1000 %s -o %s.png --background-color '#ffffff'", output_filename, output_filename);
123 | if(rsvg_command_status){
124 | system(rsvgCommand);
125 | }
126 |
127 | }
128 |
129 | static PyObject *sketchy_sketch(PyObject *self, PyObject *args){
130 | const char *inputpng = "";
131 | const char *filename = "";
132 | const char *color = "";
133 | float nibsize = 1;
134 | int linesize = 1;
135 | int maxLineLength = 50;
136 | float scale = 1.0;
137 | float sigTransX = 0.0;
138 | float sigTransY = 0.0;
139 | float sigScale = 1.0;
140 | if (!PyArg_ParseTuple(args, "ssfisfifff", &inputpng, &filename, &nibsize, &maxLineLength, &color, &scale, &linesize, &sigTransX, &sigTransY, &sigScale)){
141 | return NULL;
142 | }
143 |
144 | decodePNG(inputpng, filename, maxLineLength, nibsize, color, scale, linesize, sigTransX, sigTransY, sigScale);
145 |
146 | PyObject *ret = Py_BuildValue("i", 0);
147 | return ret;
148 | }
149 |
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/src/blackstripes/spiral.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include "Python.h"
4 | #include "../lib/sketchy/SketchyImage.h"
5 | #include "../lib/sketchy/Point.h"
6 | #include "blackstripes_signature.h"
7 | //char *signature = "\n";
8 |
9 | static char module_docstring[] = "This module provides a blackstripes spiral png to svg conversion";
10 | static char draw_docstring[] = "Make a svg blackstripes spiral of the png";
11 |
12 | static char svg_formatstring[] = "\
13 | \
14 | \n", sig);
193 | }
194 | fclose(svgFile);
195 | SketchyImage_release(im);
196 |
197 | char rsvgCommand[200];
198 | int rsvg_command_status = sprintf(rsvgCommand, "rsvg-convert -a -w 1000 %s -o %s.png --background-color '#ffffff'", output_filename, output_filename);
199 | if(rsvg_command_status){
200 | system(rsvgCommand);
201 | }
202 |
203 | }
204 |
205 | static PyObject *spiral_draw(PyObject *self, PyObject *args){
206 | const char *inputpng = "";
207 | const char *filename = "";
208 | const char *color = "";
209 | float nibsize = 1;
210 | float scale = 1.0;
211 | int level0 = 1;
212 | int level1 = 1;
213 | int level2 = 1;
214 | int level3 = 1;
215 | int linespacing = 1;
216 | float sigTransX = 0.0;
217 | float sigTransY = 0.0;
218 | float sigScale = 1.0;
219 | int roundShape = 0;
220 | if (!PyArg_ParseTuple(args, "ssfsfiiiiifff|i", &inputpng, &filename, &nibsize, &color,
221 | &scale, &level0, &level1, &level2, &level3, &linespacing,
222 | &sigTransX, &sigTransY, &sigScale, &roundShape)){
223 | return NULL;
224 | }
225 |
226 | decodePNG(inputpng, filename, nibsize, color, scale, level0, level1, level2, level3,
227 | linespacing, sigTransX, sigTransY, sigScale, roundShape);
228 |
229 | PyObject *ret = Py_BuildValue("i", 0);
230 | return ret;
231 | }
232 |
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/src/cli/blackstripes:
--------------------------------------------------------------------------------
1 | #!/usr/bin/python
2 | from blackstripes import spiral, sketchy, crossed
3 | import argparse
4 | import re
5 | import os
6 | import webbrowser
7 | import sys
8 |
9 |
10 | def hex_code(string):
11 | if re.search(r'^#?(?:[0-9a-fA-F]{3}){1,2}$', string):
12 | if string[0] != "#":
13 | string = "#" + string
14 | return string
15 | msg = "%r is not a valid hex color" % string
16 | raise argparse.ArgumentTypeError(msg)
17 |
18 |
19 | def get_output(input_path):
20 | basename = os.path.basename(input_path)
21 | name = ".".join(basename.split(".")[:-1])
22 | return name + ".svg"
23 |
24 |
25 | def get_output_png_path(output_path):
26 | return output_path + ".png"
27 |
28 |
29 | def apply_spiral(args):
30 | draw_args = [
31 | args.input_path,
32 | args.output_path,
33 | args.linewidth,
34 | args.color,
35 | args.scale
36 | ] \
37 | + args.levels \
38 | + [args.linespacing] \
39 | + args.sigtransform \
40 | + [args.round]
41 | spiral.draw(*draw_args)
42 |
43 |
44 | def apply_crossed(args):
45 | draw_args = [
46 | args.input_path,
47 | args.output_path,
48 | args.linewidth,
49 | args.color,
50 | args.scale
51 | ] \
52 | + args.levels \
53 | + [args.type] \
54 | + args.sigtransform
55 | crossed.draw(*draw_args)
56 |
57 |
58 | def apply_sketchy(args):
59 | draw_args = [
60 | args.input_path,
61 | args.output_path,
62 | args.linewidth,
63 | args.maxlinelength,
64 | args.color,
65 | args.scale,
66 | args.internallinesize,
67 | ] \
68 | + args.sigtransform
69 | sketchy.draw(*draw_args)
70 |
71 |
72 | argparser = argparse.ArgumentParser()
73 | subparsers = argparser.add_subparsers(dest="command")
74 | subparsers.required = True
75 | parser_sketchy = subparsers.add_parser('sketchy')
76 | parser_spiral = subparsers.add_parser('spiral')
77 | parser_crossed = subparsers.add_parser('crossed')
78 |
79 |
80 | class A:
81 | def __init__(self, *args, **kwargs):
82 | self.args = args
83 | self.kwargs = kwargs
84 |
85 | def go(self, parser):
86 | parser.add_argument(*self.args, **self.kwargs)
87 |
88 |
89 | queue = {
90 | parser_sketchy: [],
91 | parser_spiral: [],
92 | parser_crossed: []
93 | }
94 |
95 |
96 | def add(parsers, args):
97 | for parser in parsers:
98 | queue[parser] += args
99 |
100 |
101 | add(
102 | [parser_sketchy, parser_spiral, parser_crossed],
103 | [
104 | A("output", nargs="?"),
105 | A("input", nargs=1),
106 | A("--output", "-o"),
107 | A("--linewidth", "--nibsize",
108 | "--width", "-n", type=float, default=2.0),
109 | A("--color", "-c", type=hex_code, default="#000000"),
110 | A("--scale", "-s", type=float, default=1.0),
111 | A("--sigtransform", "--sig", "-t", nargs=3,
112 | type=float, default=[0, 0, 0], metavar=("X", "Y", "SCALE")),
113 | A("--preview-svg", action="store_true",
114 | help="preview the output svg and exit"),
115 | A("--preview-png", "--preview", "-p",
116 | action="store_true", help="preview the output png and exit")
117 | ]
118 | )
119 | add(
120 | [parser_spiral, parser_crossed],
121 | [
122 | A("--levels", nargs=4, type=int,
123 | default=[180, 108, 180, 108], metavar="LEVEL")
124 | ]
125 | )
126 | add(
127 | [parser_spiral],
128 | [
129 | A("--linespacing", "--spacing", type=int, default=2),
130 | A("--round", "-r", action="store_true")
131 | ]
132 | )
133 | add(
134 | [parser_sketchy],
135 | [
136 | A("--internallinesize", "--linesize",
137 | "-S", type=int, default=2),
138 | A("--maxlinelength", "--maxlen",
139 | "-m", type=int, default=100)
140 | ]
141 | )
142 | add(
143 | [parser_crossed],
144 | [
145 | A("--type", type=int, default=1)
146 | ]
147 | )
148 |
149 |
150 | for parser in queue:
151 | for a in queue[parser]:
152 | a.go(parser)
153 |
154 | parser_spiral.set_defaults(func=apply_spiral)
155 | parser_crossed.set_defaults(func=apply_crossed)
156 | parser_sketchy.set_defaults(func=apply_sketchy)
157 |
158 |
159 | def apply_args(str_args):
160 | args = argparser.parse_args(str_args)
161 | args.input_path = args.input[-1]
162 | args.output_path = args.output or get_output(args.input[-1])
163 | args.func(args)
164 | if args.preview_svg:
165 | webbrowser.open(args.output_path)
166 | if args.preview_png:
167 | webbrowser.open(get_output_png_path(args.output_path))
168 |
169 |
170 | if __name__ == "__main__":
171 | apply_args(sys.argv[1:])
172 |
--------------------------------------------------------------------------------
/src/lib/lodepng/lodepng.h:
--------------------------------------------------------------------------------
1 | /*
2 | LodePNG version 20141130
3 |
4 | Copyright (c) 2005-2014 Lode Vandevenne
5 |
6 | This software is provided 'as-is', without any express or implied
7 | warranty. In no event will the authors be held liable for any damages
8 | arising from the use of this software.
9 |
10 | Permission is granted to anyone to use this software for any purpose,
11 | including commercial applications, and to alter it and redistribute it
12 | freely, subject to the following restrictions:
13 |
14 | 1. The origin of this software must not be misrepresented; you must not
15 | claim that you wrote the original software. If you use this software
16 | in a product, an acknowledgment in the product documentation would be
17 | appreciated but is not required.
18 |
19 | 2. Altered source versions must be plainly marked as such, and must not be
20 | misrepresented as being the original software.
21 |
22 | 3. This notice may not be removed or altered from any source
23 | distribution.
24 | */
25 |
26 | #ifndef LODEPNG_H
27 | #define LODEPNG_H
28 |
29 | #include /*for size_t*/
30 |
31 | #ifdef __cplusplus
32 | #include
33 | #include
34 | #endif /*__cplusplus*/
35 |
36 | #define LODEPNG_VERSION_STRING "20141130"
37 |
38 | /*
39 | The following #defines are used to create code sections. They can be disabled
40 | to disable code sections, which can give faster compile time and smaller binary.
41 | The "NO_COMPILE" defines are designed to be used to pass as defines to the
42 | compiler command to disable them without modifying this header, e.g.
43 | -DLODEPNG_NO_COMPILE_ZLIB for gcc.
44 | */
45 | /*deflate & zlib. If disabled, you must specify alternative zlib functions in
46 | the custom_zlib field of the compress and decompress settings*/
47 | #ifndef LODEPNG_NO_COMPILE_ZLIB
48 | #define LODEPNG_COMPILE_ZLIB
49 | #endif
50 | /*png encoder and png decoder*/
51 | #ifndef LODEPNG_NO_COMPILE_PNG
52 | #define LODEPNG_COMPILE_PNG
53 | #endif
54 | /*deflate&zlib decoder and png decoder*/
55 | #ifndef LODEPNG_NO_COMPILE_DECODER
56 | #define LODEPNG_COMPILE_DECODER
57 | #endif
58 | /*deflate&zlib encoder and png encoder*/
59 | #ifndef LODEPNG_NO_COMPILE_ENCODER
60 | #define LODEPNG_COMPILE_ENCODER
61 | #endif
62 | /*the optional built in harddisk file loading and saving functions*/
63 | #ifndef LODEPNG_NO_COMPILE_DISK
64 | #define LODEPNG_COMPILE_DISK
65 | #endif
66 | /*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/
67 | #ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
68 | #define LODEPNG_COMPILE_ANCILLARY_CHUNKS
69 | #endif
70 | /*ability to convert error numerical codes to English text string*/
71 | #ifndef LODEPNG_NO_COMPILE_ERROR_TEXT
72 | #define LODEPNG_COMPILE_ERROR_TEXT
73 | #endif
74 | /*Compile the default allocators (C's free, malloc and realloc). If you disable this,
75 | you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your
76 | source files with custom allocators.*/
77 | #ifndef LODEPNG_NO_COMPILE_ALLOCATORS
78 | #define LODEPNG_COMPILE_ALLOCATORS
79 | #endif
80 | /*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/
81 | #ifdef __cplusplus
82 | #ifndef LODEPNG_NO_COMPILE_CPP
83 | #define LODEPNG_COMPILE_CPP
84 | #endif
85 | #endif
86 |
87 | #ifdef LODEPNG_COMPILE_PNG
88 | /*The PNG color types (also used for raw).*/
89 | typedef enum LodePNGColorType
90 | {
91 | LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/
92 | LCT_RGB = 2, /*RGB: 8,16 bit*/
93 | LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/
94 | LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/
95 | LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/
96 | } LodePNGColorType;
97 |
98 | #ifdef LODEPNG_COMPILE_DECODER
99 | /*
100 | Converts PNG data in memory to raw pixel data.
101 | out: Output parameter. Pointer to buffer that will contain the raw pixel data.
102 | After decoding, its size is w * h * (bytes per pixel) bytes larger than
103 | initially. Bytes per pixel depends on colortype and bitdepth.
104 | Must be freed after usage with free(*out).
105 | Note: for 16-bit per channel colors, uses big endian format like PNG does.
106 | w: Output parameter. Pointer to width of pixel data.
107 | h: Output parameter. Pointer to height of pixel data.
108 | in: Memory buffer with the PNG file.
109 | insize: size of the in buffer.
110 | colortype: the desired color type for the raw output image. See explanation on PNG color types.
111 | bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types.
112 | Return value: LodePNG error code (0 means no error).
113 | */
114 | unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h,
115 | const unsigned char* in, size_t insize,
116 | LodePNGColorType colortype, unsigned bitdepth);
117 |
118 | /*Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image*/
119 | unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h,
120 | const unsigned char* in, size_t insize);
121 |
122 | /*Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image*/
123 | unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h,
124 | const unsigned char* in, size_t insize);
125 |
126 | #ifdef LODEPNG_COMPILE_DISK
127 | /*
128 | Load PNG from disk, from file with given name.
129 | Same as the other decode functions, but instead takes a filename as input.
130 | */
131 | unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h,
132 | const char* filename,
133 | LodePNGColorType colortype, unsigned bitdepth);
134 |
135 | /*Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image.*/
136 | unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h,
137 | const char* filename);
138 |
139 | /*Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image.*/
140 | unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h,
141 | const char* filename);
142 | #endif /*LODEPNG_COMPILE_DISK*/
143 | #endif /*LODEPNG_COMPILE_DECODER*/
144 |
145 |
146 | #ifdef LODEPNG_COMPILE_ENCODER
147 | /*
148 | Converts raw pixel data into a PNG image in memory. The colortype and bitdepth
149 | of the output PNG image cannot be chosen, they are automatically determined
150 | by the colortype, bitdepth and content of the input pixel data.
151 | Note: for 16-bit per channel colors, needs big endian format like PNG does.
152 | out: Output parameter. Pointer to buffer that will contain the PNG image data.
153 | Must be freed after usage with free(*out).
154 | outsize: Output parameter. Pointer to the size in bytes of the out buffer.
155 | image: The raw pixel data to encode. The size of this buffer should be
156 | w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth.
157 | w: width of the raw pixel data in pixels.
158 | h: height of the raw pixel data in pixels.
159 | colortype: the color type of the raw input image. See explanation on PNG color types.
160 | bitdepth: the bit depth of the raw input image. See explanation on PNG color types.
161 | Return value: LodePNG error code (0 means no error).
162 | */
163 | unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize,
164 | const unsigned char* image, unsigned w, unsigned h,
165 | LodePNGColorType colortype, unsigned bitdepth);
166 |
167 | /*Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image.*/
168 | unsigned lodepng_encode32(unsigned char** out, size_t* outsize,
169 | const unsigned char* image, unsigned w, unsigned h);
170 |
171 | /*Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image.*/
172 | unsigned lodepng_encode24(unsigned char** out, size_t* outsize,
173 | const unsigned char* image, unsigned w, unsigned h);
174 |
175 | #ifdef LODEPNG_COMPILE_DISK
176 | /*
177 | Converts raw pixel data into a PNG file on disk.
178 | Same as the other encode functions, but instead takes a filename as output.
179 | NOTE: This overwrites existing files without warning!
180 | */
181 | unsigned lodepng_encode_file(const char* filename,
182 | const unsigned char* image, unsigned w, unsigned h,
183 | LodePNGColorType colortype, unsigned bitdepth);
184 |
185 | /*Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image.*/
186 | unsigned lodepng_encode32_file(const char* filename,
187 | const unsigned char* image, unsigned w, unsigned h);
188 |
189 | /*Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image.*/
190 | unsigned lodepng_encode24_file(const char* filename,
191 | const unsigned char* image, unsigned w, unsigned h);
192 | #endif /*LODEPNG_COMPILE_DISK*/
193 | #endif /*LODEPNG_COMPILE_ENCODER*/
194 |
195 |
196 | #ifdef LODEPNG_COMPILE_CPP
197 | namespace lodepng
198 | {
199 | #ifdef LODEPNG_COMPILE_DECODER
200 | /*Same as lodepng_decode_memory, but decodes to an std::vector. The colortype
201 | is the format to output the pixels to. Default is RGBA 8-bit per channel.*/
202 | unsigned decode(std::vector& out, unsigned& w, unsigned& h,
203 | const unsigned char* in, size_t insize,
204 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
205 | unsigned decode(std::vector& out, unsigned& w, unsigned& h,
206 | const std::vector& in,
207 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
208 | #ifdef LODEPNG_COMPILE_DISK
209 | /*
210 | Converts PNG file from disk to raw pixel data in memory.
211 | Same as the other decode functions, but instead takes a filename as input.
212 | */
213 | unsigned decode(std::vector& out, unsigned& w, unsigned& h,
214 | const std::string& filename,
215 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
216 | #endif //LODEPNG_COMPILE_DISK
217 | #endif //LODEPNG_COMPILE_DECODER
218 |
219 | #ifdef LODEPNG_COMPILE_ENCODER
220 | /*Same as lodepng_encode_memory, but encodes to an std::vector. colortype
221 | is that of the raw input data. The output PNG color type will be auto chosen.*/
222 | unsigned encode(std::vector& out,
223 | const unsigned char* in, unsigned w, unsigned h,
224 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
225 | unsigned encode(std::vector& out,
226 | const std::vector& in, unsigned w, unsigned h,
227 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
228 | #ifdef LODEPNG_COMPILE_DISK
229 | /*
230 | Converts 32-bit RGBA raw pixel data into a PNG file on disk.
231 | Same as the other encode functions, but instead takes a filename as output.
232 | NOTE: This overwrites existing files without warning!
233 | */
234 | unsigned encode(const std::string& filename,
235 | const unsigned char* in, unsigned w, unsigned h,
236 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
237 | unsigned encode(const std::string& filename,
238 | const std::vector& in, unsigned w, unsigned h,
239 | LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
240 | #endif //LODEPNG_COMPILE_DISK
241 | #endif //LODEPNG_COMPILE_ENCODER
242 | } //namespace lodepng
243 | #endif /*LODEPNG_COMPILE_CPP*/
244 | #endif /*LODEPNG_COMPILE_PNG*/
245 |
246 | #ifdef LODEPNG_COMPILE_ERROR_TEXT
247 | /*Returns an English description of the numerical error code.*/
248 | const char* lodepng_error_text(unsigned code);
249 | #endif /*LODEPNG_COMPILE_ERROR_TEXT*/
250 |
251 | #ifdef LODEPNG_COMPILE_DECODER
252 | /*Settings for zlib decompression*/
253 | typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
254 | struct LodePNGDecompressSettings
255 | {
256 | unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
257 |
258 | /*use custom zlib decoder instead of built in one (default: null)*/
259 | unsigned (*custom_zlib)(unsigned char**, size_t*,
260 | const unsigned char*, size_t,
261 | const LodePNGDecompressSettings*);
262 | /*use custom deflate decoder instead of built in one (default: null)
263 | if custom_zlib is used, custom_deflate is ignored since only the built in
264 | zlib function will call custom_deflate*/
265 | unsigned (*custom_inflate)(unsigned char**, size_t*,
266 | const unsigned char*, size_t,
267 | const LodePNGDecompressSettings*);
268 |
269 | const void* custom_context; /*optional custom settings for custom functions*/
270 | };
271 |
272 | extern const LodePNGDecompressSettings lodepng_default_decompress_settings;
273 | void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings);
274 | #endif /*LODEPNG_COMPILE_DECODER*/
275 |
276 | #ifdef LODEPNG_COMPILE_ENCODER
277 | /*
278 | Settings for zlib compression. Tweaking these settings tweaks the balance
279 | between speed and compression ratio.
280 | */
281 | typedef struct LodePNGCompressSettings LodePNGCompressSettings;
282 | struct LodePNGCompressSettings /*deflate = compress*/
283 | {
284 | /*LZ77 related settings*/
285 | unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
286 | unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
287 | unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/
288 | unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
289 | unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/
290 | unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/
291 |
292 | /*use custom zlib encoder instead of built in one (default: null)*/
293 | unsigned (*custom_zlib)(unsigned char**, size_t*,
294 | const unsigned char*, size_t,
295 | const LodePNGCompressSettings*);
296 | /*use custom deflate encoder instead of built in one (default: null)
297 | if custom_zlib is used, custom_deflate is ignored since only the built in
298 | zlib function will call custom_deflate*/
299 | unsigned (*custom_deflate)(unsigned char**, size_t*,
300 | const unsigned char*, size_t,
301 | const LodePNGCompressSettings*);
302 |
303 | const void* custom_context; /*optional custom settings for custom functions*/
304 | };
305 |
306 | extern const LodePNGCompressSettings lodepng_default_compress_settings;
307 | void lodepng_compress_settings_init(LodePNGCompressSettings* settings);
308 | #endif /*LODEPNG_COMPILE_ENCODER*/
309 |
310 | #ifdef LODEPNG_COMPILE_PNG
311 | /*
312 | Color mode of an image. Contains all information required to decode the pixel
313 | bits to RGBA colors. This information is the same as used in the PNG file
314 | format, and is used both for PNG and raw image data in LodePNG.
315 | */
316 | typedef struct LodePNGColorMode
317 | {
318 | /*header (IHDR)*/
319 | LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/
320 | unsigned bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/
321 |
322 | /*
323 | palette (PLTE and tRNS)
324 |
325 | Dynamically allocated with the colors of the palette, including alpha.
326 | When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use
327 | lodepng_palette_clear, then for each color use lodepng_palette_add.
328 | If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
329 |
330 | When decoding, by default you can ignore this palette, since LodePNG already
331 | fills the palette colors in the pixels of the raw RGBA output.
332 |
333 | The palette is only supported for color type 3.
334 | */
335 | unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/
336 | size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/
337 |
338 | /*
339 | transparent color key (tRNS)
340 |
341 | This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
342 | For greyscale PNGs, r, g and b will all 3 be set to the same.
343 |
344 | When decoding, by default you can ignore this information, since LodePNG sets
345 | pixels with this key to transparent already in the raw RGBA output.
346 |
347 | The color key is only supported for color types 0 and 2.
348 | */
349 | unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
350 | unsigned key_r; /*red/greyscale component of color key*/
351 | unsigned key_g; /*green component of color key*/
352 | unsigned key_b; /*blue component of color key*/
353 | } LodePNGColorMode;
354 |
355 | /*init, cleanup and copy functions to use with this struct*/
356 | void lodepng_color_mode_init(LodePNGColorMode* info);
357 | void lodepng_color_mode_cleanup(LodePNGColorMode* info);
358 | /*return value is error code (0 means no error)*/
359 | unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source);
360 |
361 | void lodepng_palette_clear(LodePNGColorMode* info);
362 | /*add 1 color to the palette*/
363 | unsigned lodepng_palette_add(LodePNGColorMode* info,
364 | unsigned char r, unsigned char g, unsigned char b, unsigned char a);
365 |
366 | /*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/
367 | unsigned lodepng_get_bpp(const LodePNGColorMode* info);
368 | /*get the amount of color channels used, based on colortype in the struct.
369 | If a palette is used, it counts as 1 channel.*/
370 | unsigned lodepng_get_channels(const LodePNGColorMode* info);
371 | /*is it a greyscale type? (only colortype 0 or 4)*/
372 | unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info);
373 | /*has it got an alpha channel? (only colortype 2 or 6)*/
374 | unsigned lodepng_is_alpha_type(const LodePNGColorMode* info);
375 | /*has it got a palette? (only colortype 3)*/
376 | unsigned lodepng_is_palette_type(const LodePNGColorMode* info);
377 | /*only returns true if there is a palette and there is a value in the palette with alpha < 255.
378 | Loops through the palette to check this.*/
379 | unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info);
380 | /*
381 | Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
382 | Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
383 | Returns false if the image can only have opaque pixels.
384 | In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
385 | or if "key_defined" is true.
386 | */
387 | unsigned lodepng_can_have_alpha(const LodePNGColorMode* info);
388 | /*Returns the byte size of a raw image buffer with given width, height and color mode*/
389 | size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color);
390 |
391 | #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
392 | /*The information of a Time chunk in PNG.*/
393 | typedef struct LodePNGTime
394 | {
395 | unsigned year; /*2 bytes used (0-65535)*/
396 | unsigned month; /*1-12*/
397 | unsigned day; /*1-31*/
398 | unsigned hour; /*0-23*/
399 | unsigned minute; /*0-59*/
400 | unsigned second; /*0-60 (to allow for leap seconds)*/
401 | } LodePNGTime;
402 | #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
403 |
404 | /*Information about the PNG image, except pixels, width and height.*/
405 | typedef struct LodePNGInfo
406 | {
407 | /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/
408 | unsigned compression_method;/*compression method of the original file. Always 0.*/
409 | unsigned filter_method; /*filter method of the original file*/
410 | unsigned interlace_method; /*interlace method of the original file*/
411 | LodePNGColorMode color; /*color type and bits, palette and transparency of the PNG file*/
412 |
413 | #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
414 | /*
415 | suggested background color chunk (bKGD)
416 | This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.
417 |
418 | For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
419 | the encoder writes the red one. For palette PNGs: When decoding, the RGB value
420 | will be stored, not a palette index. But when encoding, specify the index of
421 | the palette in background_r, the other two are then ignored.
422 |
423 | The decoder does not use this background color to edit the color of pixels.
424 | */
425 | unsigned background_defined; /*is a suggested background color given?*/
426 | unsigned background_r; /*red component of suggested background color*/
427 | unsigned background_g; /*green component of suggested background color*/
428 | unsigned background_b; /*blue component of suggested background color*/
429 |
430 | /*
431 | non-international text chunks (tEXt and zTXt)
432 |
433 | The char** arrays each contain num strings. The actual messages are in
434 | text_strings, while text_keys are keywords that give a short description what
435 | the actual text represents, e.g. Title, Author, Description, or anything else.
436 |
437 | A keyword is minimum 1 character and maximum 79 characters long. It's
438 | discouraged to use a single line length longer than 79 characters for texts.
439 |
440 | Don't allocate these text buffers yourself. Use the init/cleanup functions
441 | correctly and use lodepng_add_text and lodepng_clear_text.
442 | */
443 | size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
444 | char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/
445 | char** text_strings; /*the actual text*/
446 |
447 | /*
448 | international text chunks (iTXt)
449 | Similar to the non-international text chunks, but with additional strings
450 | "langtags" and "transkeys".
451 | */
452 | size_t itext_num; /*the amount of international texts in this PNG*/
453 | char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/
454 | char** itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
455 | char** itext_transkeys; /*keyword translated to the international language - UTF-8 string*/
456 | char** itext_strings; /*the actual international text - UTF-8 string*/
457 |
458 | /*time chunk (tIME)*/
459 | unsigned time_defined; /*set to 1 to make the encoder generate a tIME chunk*/
460 | LodePNGTime time;
461 |
462 | /*phys chunk (pHYs)*/
463 | unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/
464 | unsigned phys_x; /*pixels per unit in x direction*/
465 | unsigned phys_y; /*pixels per unit in y direction*/
466 | unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
467 |
468 | /*
469 | unknown chunks
470 | There are 3 buffers, one for each position in the PNG where unknown chunks can appear
471 | each buffer contains all unknown chunks for that position consecutively
472 | The 3 buffers are the unknown chunks between certain critical chunks:
473 | 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND
474 | Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
475 | later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.
476 | */
477 | unsigned char* unknown_chunks_data[3];
478 | size_t unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/
479 | #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
480 | } LodePNGInfo;
481 |
482 | /*init, cleanup and copy functions to use with this struct*/
483 | void lodepng_info_init(LodePNGInfo* info);
484 | void lodepng_info_cleanup(LodePNGInfo* info);
485 | /*return value is error code (0 means no error)*/
486 | unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source);
487 |
488 | #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
489 | void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
490 | unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/
491 |
492 | void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/
493 | unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
494 | const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/
495 | #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
496 |
497 | /*
498 | Converts raw buffer from one color type to another color type, based on
499 | LodePNGColorMode structs to describe the input and output color type.
500 | See the reference manual at the end of this header file to see which color conversions are supported.
501 | return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
502 | The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
503 | of the output color type (lodepng_get_bpp).
504 | For < 8 bpp images, there should not be padding bits at the end of scanlines.
505 | For 16-bit per channel colors, uses big endian format like PNG does.
506 | Return value is LodePNG error code
507 | */
508 | unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
509 | LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
510 | unsigned w, unsigned h);
511 |
512 | #ifdef LODEPNG_COMPILE_DECODER
513 | /*
514 | Settings for the decoder. This contains settings for the PNG and the Zlib
515 | decoder, but not the Info settings from the Info structs.
516 | */
517 | typedef struct LodePNGDecoderSettings
518 | {
519 | LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
520 |
521 | unsigned ignore_crc; /*ignore CRC checksums*/
522 |
523 | unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
524 |
525 | #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
526 | unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/
527 | /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/
528 | unsigned remember_unknown_chunks;
529 | #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
530 | } LodePNGDecoderSettings;
531 |
532 | void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings);
533 | #endif /*LODEPNG_COMPILE_DECODER*/
534 |
535 | #ifdef LODEPNG_COMPILE_ENCODER
536 | /*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/
537 | typedef enum LodePNGFilterStrategy
538 | {
539 | /*every filter at zero*/
540 | LFS_ZERO,
541 | /*Use filter that gives minumum sum, as described in the official PNG filter heuristic.*/
542 | LFS_MINSUM,
543 | /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
544 | on the image, this is better or worse than minsum.*/
545 | LFS_ENTROPY,
546 | /*
547 | Brute-force-search PNG filters by compressing each filter for each scanline.
548 | Experimental, very slow, and only rarely gives better compression than MINSUM.
549 | */
550 | LFS_BRUTE_FORCE,
551 | /*use predefined_filters buffer: you specify the filter type for each scanline*/
552 | LFS_PREDEFINED
553 | } LodePNGFilterStrategy;
554 |
555 | /*Gives characteristics about the colors of the image, which helps decide which color model to use for encoding.
556 | Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/
557 | typedef struct LodePNGColorProfile
558 | {
559 | unsigned colored; /*not greyscale*/
560 | unsigned key; /*if true, image is not opaque. Only if true and alpha is false, color key is possible.*/
561 | unsigned short key_r; /*these values are always in 16-bit bitdepth in the profile*/
562 | unsigned short key_g;
563 | unsigned short key_b;
564 | unsigned alpha; /*alpha channel or alpha palette required*/
565 | unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16.*/
566 | unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order*/
567 | unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for greyscale only. 16 if 16-bit per channel required.*/
568 | } LodePNGColorProfile;
569 |
570 | void lodepng_color_profile_init(LodePNGColorProfile* profile);
571 |
572 | /*Get a LodePNGColorProfile of the image.*/
573 | unsigned lodepng_get_color_profile(LodePNGColorProfile* profile,
574 | const unsigned char* image, unsigned w, unsigned h,
575 | const LodePNGColorMode* mode_in);
576 | /*The function LodePNG uses internally to decide the PNG color with auto_convert.
577 | Chooses an optimal color model, e.g. grey if only grey pixels, palette if < 256 colors, ...*/
578 | unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
579 | const unsigned char* image, unsigned w, unsigned h,
580 | const LodePNGColorMode* mode_in);
581 |
582 | /*Settings for the encoder.*/
583 | typedef struct LodePNGEncoderSettings
584 | {
585 | LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
586 |
587 | unsigned auto_convert; /*automatically choose output PNG color type. Default: true*/
588 |
589 | /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
590 | 8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
591 | completely follow the official PNG heuristic, filter_palette_zero must be true and
592 | filter_strategy must be LFS_MINSUM*/
593 | unsigned filter_palette_zero;
594 | /*Which filter strategy to use when not using zeroes due to filter_palette_zero.
595 | Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/
596 | LodePNGFilterStrategy filter_strategy;
597 | /*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
598 | the same length as the amount of scanlines in the image, and each value must <= 5. You
599 | have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero
600 | must be set to 0 to ensure this is also used on palette or low bitdepth images.*/
601 | const unsigned char* predefined_filters;
602 |
603 | /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
604 | If colortype is 3, PLTE is _always_ created.*/
605 | unsigned force_palette;
606 | #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
607 | /*add LodePNG identifier and version as a text chunk, for debugging*/
608 | unsigned add_id;
609 | /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
610 | unsigned text_compression;
611 | #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
612 | } LodePNGEncoderSettings;
613 |
614 | void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings);
615 | #endif /*LODEPNG_COMPILE_ENCODER*/
616 |
617 |
618 | #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
619 | /*The settings, state and information for extended encoding and decoding.*/
620 | typedef struct LodePNGState
621 | {
622 | #ifdef LODEPNG_COMPILE_DECODER
623 | LodePNGDecoderSettings decoder; /*the decoding settings*/
624 | #endif /*LODEPNG_COMPILE_DECODER*/
625 | #ifdef LODEPNG_COMPILE_ENCODER
626 | LodePNGEncoderSettings encoder; /*the encoding settings*/
627 | #endif /*LODEPNG_COMPILE_ENCODER*/
628 | LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/
629 | LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/
630 | unsigned error;
631 | #ifdef LODEPNG_COMPILE_CPP
632 | //For the lodepng::State subclass.
633 | virtual ~LodePNGState(){}
634 | #endif
635 | } LodePNGState;
636 |
637 | /*init, cleanup and copy functions to use with this struct*/
638 | void lodepng_state_init(LodePNGState* state);
639 | void lodepng_state_cleanup(LodePNGState* state);
640 | void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source);
641 | #endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
642 |
643 | #ifdef LODEPNG_COMPILE_DECODER
644 | /*
645 | Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and
646 | getting much more information about the PNG image and color mode.
647 | */
648 | unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
649 | LodePNGState* state,
650 | const unsigned char* in, size_t insize);
651 |
652 | /*
653 | Read the PNG header, but not the actual data. This returns only the information
654 | that is in the header chunk of the PNG, such as width, height and color type. The
655 | information is placed in the info_png field of the LodePNGState.
656 | */
657 | unsigned lodepng_inspect(unsigned* w, unsigned* h,
658 | LodePNGState* state,
659 | const unsigned char* in, size_t insize);
660 | #endif /*LODEPNG_COMPILE_DECODER*/
661 |
662 |
663 | #ifdef LODEPNG_COMPILE_ENCODER
664 | /*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
665 | unsigned lodepng_encode(unsigned char** out, size_t* outsize,
666 | const unsigned char* image, unsigned w, unsigned h,
667 | LodePNGState* state);
668 | #endif /*LODEPNG_COMPILE_ENCODER*/
669 |
670 | /*
671 | The lodepng_chunk functions are normally not needed, except to traverse the
672 | unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
673 | It also allows traversing the chunks of an encoded PNG file yourself.
674 |
675 | PNG standard chunk naming conventions:
676 | First byte: uppercase = critical, lowercase = ancillary
677 | Second byte: uppercase = public, lowercase = private
678 | Third byte: must be uppercase
679 | Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
680 | */
681 |
682 | /*
683 | Gets the length of the data of the chunk. Total chunk length has 12 bytes more.
684 | There must be at least 4 bytes to read from. If the result value is too large,
685 | it may be corrupt data.
686 | */
687 | unsigned lodepng_chunk_length(const unsigned char* chunk);
688 |
689 | /*puts the 4-byte type in null terminated string*/
690 | void lodepng_chunk_type(char type[5], const unsigned char* chunk);
691 |
692 | /*check if the type is the given type*/
693 | unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type);
694 |
695 | /*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/
696 | unsigned char lodepng_chunk_ancillary(const unsigned char* chunk);
697 |
698 | /*0: public, 1: private (see PNG standard)*/
699 | unsigned char lodepng_chunk_private(const unsigned char* chunk);
700 |
701 | /*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/
702 | unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk);
703 |
704 | /*get pointer to the data of the chunk, where the input points to the header of the chunk*/
705 | unsigned char* lodepng_chunk_data(unsigned char* chunk);
706 | const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk);
707 |
708 | /*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/
709 | unsigned lodepng_chunk_check_crc(const unsigned char* chunk);
710 |
711 | /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
712 | void lodepng_chunk_generate_crc(unsigned char* chunk);
713 |
714 | /*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/
715 | unsigned char* lodepng_chunk_next(unsigned char* chunk);
716 | const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk);
717 |
718 | /*
719 | Appends chunk to the data in out. The given chunk should already have its chunk header.
720 | The out variable and outlength are updated to reflect the new reallocated buffer.
721 | Returns error code (0 if it went ok)
722 | */
723 | unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk);
724 |
725 | /*
726 | Appends new chunk to out. The chunk to append is given by giving its length, type
727 | and data separately. The type is a 4-letter string.
728 | The out variable and outlength are updated to reflect the new reallocated buffer.
729 | Returne error code (0 if it went ok)
730 | */
731 | unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
732 | const char* type, const unsigned char* data);
733 |
734 |
735 | /*Calculate CRC32 of buffer*/
736 | unsigned lodepng_crc32(const unsigned char* buf, size_t len);
737 | #endif /*LODEPNG_COMPILE_PNG*/
738 |
739 |
740 | #ifdef LODEPNG_COMPILE_ZLIB
741 | /*
742 | This zlib part can be used independently to zlib compress and decompress a
743 | buffer. It cannot be used to create gzip files however, and it only supports the
744 | part of zlib that is required for PNG, it does not support dictionaries.
745 | */
746 |
747 | #ifdef LODEPNG_COMPILE_DECODER
748 | /*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/
749 | unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
750 | const unsigned char* in, size_t insize,
751 | const LodePNGDecompressSettings* settings);
752 |
753 | /*
754 | Decompresses Zlib data. Reallocates the out buffer and appends the data. The
755 | data must be according to the zlib specification.
756 | Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
757 | buffer and *outsize its size in bytes. out must be freed by user after usage.
758 | */
759 | unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize,
760 | const unsigned char* in, size_t insize,
761 | const LodePNGDecompressSettings* settings);
762 | #endif /*LODEPNG_COMPILE_DECODER*/
763 |
764 | #ifdef LODEPNG_COMPILE_ENCODER
765 | /*
766 | Compresses data with Zlib. Reallocates the out buffer and appends the data.
767 | Zlib adds a small header and trailer around the deflate data.
768 | The data is output in the format of the zlib specification.
769 | Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
770 | buffer and *outsize its size in bytes. out must be freed by user after usage.
771 | */
772 | unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize,
773 | const unsigned char* in, size_t insize,
774 | const LodePNGCompressSettings* settings);
775 |
776 | /*
777 | Find length-limited Huffman code for given frequencies. This function is in the
778 | public interface only for tests, it's used internally by lodepng_deflate.
779 | */
780 | unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
781 | size_t numcodes, unsigned maxbitlen);
782 |
783 | /*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/
784 | unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
785 | const unsigned char* in, size_t insize,
786 | const LodePNGCompressSettings* settings);
787 |
788 | #endif /*LODEPNG_COMPILE_ENCODER*/
789 | #endif /*LODEPNG_COMPILE_ZLIB*/
790 |
791 | #ifdef LODEPNG_COMPILE_DISK
792 | /*
793 | Load a file from disk into buffer. The function allocates the out buffer, and
794 | after usage you should free it.
795 | out: output parameter, contains pointer to loaded buffer.
796 | outsize: output parameter, size of the allocated out buffer
797 | filename: the path to the file to load
798 | return value: error code (0 means ok)
799 | */
800 | unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename);
801 |
802 | /*
803 | Save a file from buffer to disk. Warning, if it exists, this function overwrites
804 | the file without warning!
805 | buffer: the buffer to write
806 | buffersize: size of the buffer to write
807 | filename: the path to the file to save to
808 | return value: error code (0 means ok)
809 | */
810 | unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename);
811 | #endif /*LODEPNG_COMPILE_DISK*/
812 |
813 | #ifdef LODEPNG_COMPILE_CPP
814 | //The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers.
815 | namespace lodepng
816 | {
817 | #ifdef LODEPNG_COMPILE_PNG
818 | class State : public LodePNGState
819 | {
820 | public:
821 | State();
822 | State(const State& other);
823 | virtual ~State();
824 | State& operator=(const State& other);
825 | };
826 |
827 | #ifdef LODEPNG_COMPILE_DECODER
828 | //Same as other lodepng::decode, but using a State for more settings and information.
829 | unsigned decode(std::vector& out, unsigned& w, unsigned& h,
830 | State& state,
831 | const unsigned char* in, size_t insize);
832 | unsigned decode(std::vector& out, unsigned& w, unsigned& h,
833 | State& state,
834 | const std::vector& in);
835 | #endif /*LODEPNG_COMPILE_DECODER*/
836 |
837 | #ifdef LODEPNG_COMPILE_ENCODER
838 | //Same as other lodepng::encode, but using a State for more settings and information.
839 | unsigned encode(std::vector& out,
840 | const unsigned char* in, unsigned w, unsigned h,
841 | State& state);
842 | unsigned encode(std::vector& out,
843 | const std::vector& in, unsigned w, unsigned h,
844 | State& state);
845 | #endif /*LODEPNG_COMPILE_ENCODER*/
846 |
847 | #ifdef LODEPNG_COMPILE_DISK
848 | /*
849 | Load a file from disk into an std::vector. If the vector is empty, then either
850 | the file doesn't exist or is an empty file.
851 | */
852 | void load_file(std::vector& buffer, const std::string& filename);
853 |
854 | /*
855 | Save the binary data in an std::vector to a file on disk. The file is overwritten
856 | without warning.
857 | */
858 | void save_file(const std::vector& buffer, const std::string& filename);
859 | #endif //LODEPNG_COMPILE_DISK
860 | #endif //LODEPNG_COMPILE_PNG
861 |
862 | #ifdef LODEPNG_COMPILE_ZLIB
863 | #ifdef LODEPNG_COMPILE_DECODER
864 | //Zlib-decompress an unsigned char buffer
865 | unsigned decompress(std::vector& out, const unsigned char* in, size_t insize,
866 | const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
867 |
868 | //Zlib-decompress an std::vector
869 | unsigned decompress(std::vector& out, const std::vector& in,
870 | const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
871 | #endif //LODEPNG_COMPILE_DECODER
872 |
873 | #ifdef LODEPNG_COMPILE_ENCODER
874 | //Zlib-compress an unsigned char buffer
875 | unsigned compress(std::vector& out, const unsigned char* in, size_t insize,
876 | const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
877 |
878 | //Zlib-compress an std::vector
879 | unsigned compress(std::vector& out, const std::vector& in,
880 | const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
881 | #endif //LODEPNG_COMPILE_ENCODER
882 | #endif //LODEPNG_COMPILE_ZLIB
883 | } //namespace lodepng
884 | #endif /*LODEPNG_COMPILE_CPP*/
885 |
886 | /*
887 | TODO:
888 | [.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
889 | [.] check compatibility with vareous compilers - done but needs to be redone for every newer version
890 | [X] converting color to 16-bit per channel types
891 | [ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values)
892 | [ ] make sure encoder generates no chunks with size > (2^31)-1
893 | [ ] partial decoding (stream processing)
894 | [X] let the "isFullyOpaque" function check color keys and transparent palettes too
895 | [X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
896 | [ ] don't stop decoding on errors like 69, 57, 58 (make warnings)
897 | [ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not
898 | [ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
899 | */
900 |
901 | #endif /*LODEPNG_H inclusion guard*/
902 |
903 | /*
904 | LodePNG Documentation
905 | ---------------------
906 |
907 | 0. table of contents
908 | --------------------
909 |
910 | 1. about
911 | 1.1. supported features
912 | 1.2. features not supported
913 | 2. C and C++ version
914 | 3. security
915 | 4. decoding
916 | 5. encoding
917 | 6. color conversions
918 | 6.1. PNG color types
919 | 6.2. color conversions
920 | 6.3. padding bits
921 | 6.4. A note about 16-bits per channel and endianness
922 | 7. error values
923 | 8. chunks and PNG editing
924 | 9. compiler support
925 | 10. examples
926 | 10.1. decoder C++ example
927 | 10.2. decoder C example
928 | 11. changes
929 | 12. contact information
930 |
931 |
932 | 1. about
933 | --------
934 |
935 | PNG is a file format to store raster images losslessly with good compression,
936 | supporting different color types and alpha channel.
937 |
938 | LodePNG is a PNG codec according to the Portable Network Graphics (PNG)
939 | Specification (Second Edition) - W3C Recommendation 10 November 2003.
940 |
941 | The specifications used are:
942 |
943 | *) Portable Network Graphics (PNG) Specification (Second Edition):
944 | http://www.w3.org/TR/2003/REC-PNG-20031110
945 | *) RFC 1950 ZLIB Compressed Data Format version 3.3:
946 | http://www.gzip.org/zlib/rfc-zlib.html
947 | *) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3:
948 | http://www.gzip.org/zlib/rfc-deflate.html
949 |
950 | The most recent version of LodePNG can currently be found at
951 | http://lodev.org/lodepng/
952 |
953 | LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds
954 | extra functionality.
955 |
956 | LodePNG exists out of two files:
957 | -lodepng.h: the header file for both C and C++
958 | -lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage
959 |
960 | If you want to start using LodePNG right away without reading this doc, get the
961 | examples from the LodePNG website to see how to use it in code, or check the
962 | smaller examples in chapter 13 here.
963 |
964 | LodePNG is simple but only supports the basic requirements. To achieve
965 | simplicity, the following design choices were made: There are no dependencies
966 | on any external library. There are functions to decode and encode a PNG with
967 | a single function call, and extended versions of these functions taking a
968 | LodePNGState struct allowing to specify or get more information. By default
969 | the colors of the raw image are always RGB or RGBA, no matter what color type
970 | the PNG file uses. To read and write files, there are simple functions to
971 | convert the files to/from buffers in memory.
972 |
973 | This all makes LodePNG suitable for loading textures in games, demos and small
974 | programs, ... It's less suitable for full fledged image editors, loading PNGs
975 | over network (it requires all the image data to be available before decoding can
976 | begin), life-critical systems, ...
977 |
978 | 1.1. supported features
979 | -----------------------
980 |
981 | The following features are supported by the decoder:
982 |
983 | *) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image,
984 | or the same color type as the PNG
985 | *) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image
986 | *) Adam7 interlace and deinterlace for any color type
987 | *) loading the image from harddisk or decoding it from a buffer from other sources than harddisk
988 | *) support for alpha channels, including RGBA color model, translucent palettes and color keying
989 | *) zlib decompression (inflate)
990 | *) zlib compression (deflate)
991 | *) CRC32 and ADLER32 checksums
992 | *) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
993 | *) the following chunks are supported (generated/interpreted) by both encoder and decoder:
994 | IHDR: header information
995 | PLTE: color palette
996 | IDAT: pixel data
997 | IEND: the final chunk
998 | tRNS: transparency for palettized images
999 | tEXt: textual information
1000 | zTXt: compressed textual information
1001 | iTXt: international textual information
1002 | bKGD: suggested background color
1003 | pHYs: physical dimensions
1004 | tIME: modification time
1005 |
1006 | 1.2. features not supported
1007 | ---------------------------
1008 |
1009 | The following features are _not_ supported:
1010 |
1011 | *) some features needed to make a conformant PNG-Editor might be still missing.
1012 | *) partial loading/stream processing. All data must be available and is processed in one call.
1013 | *) The following public chunks are not supported but treated as unknown chunks by LodePNG
1014 | cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
1015 | Some of these are not supported on purpose: LodePNG wants to provide the RGB values
1016 | stored in the pixels, not values modified by system dependent gamma or color models.
1017 |
1018 |
1019 | 2. C and C++ version
1020 | --------------------
1021 |
1022 | The C version uses buffers allocated with alloc that you need to free()
1023 | yourself. You need to use init and cleanup functions for each struct whenever
1024 | using a struct from the C version to avoid exploits and memory leaks.
1025 |
1026 | The C++ version has extra functions with std::vectors in the interface and the
1027 | lodepng::State class which is a LodePNGState with constructor and destructor.
1028 |
1029 | These files work without modification for both C and C++ compilers because all
1030 | the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers
1031 | ignore it, and the C code is made to compile both with strict ISO C90 and C++.
1032 |
1033 | To use the C++ version, you need to rename the source file to lodepng.cpp
1034 | (instead of lodepng.c), and compile it with a C++ compiler.
1035 |
1036 | To use the C version, you need to rename the source file to lodepng.c (instead
1037 | of lodepng.cpp), and compile it with a C compiler.
1038 |
1039 |
1040 | 3. Security
1041 | -----------
1042 |
1043 | Even if carefully designed, it's always possible that LodePNG contains possible
1044 | exploits. If you discover one, please let me know, and it will be fixed.
1045 |
1046 | When using LodePNG, care has to be taken with the C version of LodePNG, as well
1047 | as the C-style structs when working with C++. The following conventions are used
1048 | for all C-style structs:
1049 |
1050 | -if a struct has a corresponding init function, always call the init function when making a new one
1051 | -if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks
1052 | -if a struct has a corresponding copy function, use the copy function instead of "=".
1053 | The destination must also be inited already.
1054 |
1055 |
1056 | 4. Decoding
1057 | -----------
1058 |
1059 | Decoding converts a PNG compressed image to a raw pixel buffer.
1060 |
1061 | Most documentation on using the decoder is at its declarations in the header
1062 | above. For C, simple decoding can be done with functions such as
1063 | lodepng_decode32, and more advanced decoding can be done with the struct
1064 | LodePNGState and lodepng_decode. For C++, all decoding can be done with the
1065 | various lodepng::decode functions, and lodepng::State can be used for advanced
1066 | features.
1067 |
1068 | When using the LodePNGState, it uses the following fields for decoding:
1069 | *) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here
1070 | *) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get
1071 | *) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use
1072 |
1073 | LodePNGInfo info_png
1074 | --------------------
1075 |
1076 | After decoding, this contains extra information of the PNG image, except the actual
1077 | pixels, width and height because these are already gotten directly from the decoder
1078 | functions.
1079 |
1080 | It contains for example the original color type of the PNG image, text comments,
1081 | suggested background color, etc... More details about the LodePNGInfo struct are
1082 | at its declaration documentation.
1083 |
1084 | LodePNGColorMode info_raw
1085 | -------------------------
1086 |
1087 | When decoding, here you can specify which color type you want
1088 | the resulting raw image to be. If this is different from the colortype of the
1089 | PNG, then the decoder will automatically convert the result. This conversion
1090 | always works, except if you want it to convert a color PNG to greyscale or to
1091 | a palette with missing colors.
1092 |
1093 | By default, 32-bit color is used for the result.
1094 |
1095 | LodePNGDecoderSettings decoder
1096 | ------------------------------
1097 |
1098 | The settings can be used to ignore the errors created by invalid CRC and Adler32
1099 | chunks, and to disable the decoding of tEXt chunks.
1100 |
1101 | There's also a setting color_convert, true by default. If false, no conversion
1102 | is done, the resulting data will be as it was in the PNG (after decompression)
1103 | and you'll have to puzzle the colors of the pixels together yourself using the
1104 | color type information in the LodePNGInfo.
1105 |
1106 |
1107 | 5. Encoding
1108 | -----------
1109 |
1110 | Encoding converts a raw pixel buffer to a PNG compressed image.
1111 |
1112 | Most documentation on using the encoder is at its declarations in the header
1113 | above. For C, simple encoding can be done with functions such as
1114 | lodepng_encode32, and more advanced decoding can be done with the struct
1115 | LodePNGState and lodepng_encode. For C++, all encoding can be done with the
1116 | various lodepng::encode functions, and lodepng::State can be used for advanced
1117 | features.
1118 |
1119 | Like the decoder, the encoder can also give errors. However it gives less errors
1120 | since the encoder input is trusted, the decoder input (a PNG image that could
1121 | be forged by anyone) is not trusted.
1122 |
1123 | When using the LodePNGState, it uses the following fields for encoding:
1124 | *) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be.
1125 | *) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has
1126 | *) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use
1127 |
1128 | LodePNGInfo info_png
1129 | --------------------
1130 |
1131 | When encoding, you use this the opposite way as when decoding: for encoding,
1132 | you fill in the values you want the PNG to have before encoding. By default it's
1133 | not needed to specify a color type for the PNG since it's automatically chosen,
1134 | but it's possible to choose it yourself given the right settings.
1135 |
1136 | The encoder will not always exactly match the LodePNGInfo struct you give,
1137 | it tries as close as possible. Some things are ignored by the encoder. The
1138 | encoder uses, for example, the following settings from it when applicable:
1139 | colortype and bitdepth, text chunks, time chunk, the color key, the palette, the
1140 | background color, the interlace method, unknown chunks, ...
1141 |
1142 | When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk.
1143 | If the palette contains any colors for which the alpha channel is not 255 (so
1144 | there are translucent colors in the palette), it'll add a tRNS chunk.
1145 |
1146 | LodePNGColorMode info_raw
1147 | -------------------------
1148 |
1149 | You specify the color type of the raw image that you give to the input here,
1150 | including a possible transparent color key and palette you happen to be using in
1151 | your raw image data.
1152 |
1153 | By default, 32-bit color is assumed, meaning your input has to be in RGBA
1154 | format with 4 bytes (unsigned chars) per pixel.
1155 |
1156 | LodePNGEncoderSettings encoder
1157 | ------------------------------
1158 |
1159 | The following settings are supported (some are in sub-structs):
1160 | *) auto_convert: when this option is enabled, the encoder will
1161 | automatically choose the smallest possible color mode (including color key) that
1162 | can encode the colors of all pixels without information loss.
1163 | *) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree,
1164 | 2 = dynamic huffman tree (best compression). Should be 2 for proper
1165 | compression.
1166 | *) use_lz77: whether or not to use LZ77 for compressed block types. Should be
1167 | true for proper compression.
1168 | *) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value
1169 | 2048 by default, but can be set to 32768 for better, but slow, compression.
1170 | *) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE
1171 | chunk if force_palette is true. This can used as suggested palette to convert
1172 | to by viewers that don't support more than 256 colors (if those still exist)
1173 | *) add_id: add text chunk "Encoder: LodePNG " to the image.
1174 | *) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks.
1175 | zTXt chunks use zlib compression on the text. This gives a smaller result on
1176 | large texts but a larger result on small texts (such as a single program name).
1177 | It's all tEXt or all zTXt though, there's no separate setting per text yet.
1178 |
1179 |
1180 | 6. color conversions
1181 | --------------------
1182 |
1183 | An important thing to note about LodePNG, is that the color type of the PNG, and
1184 | the color type of the raw image, are completely independent. By default, when
1185 | you decode a PNG, you get the result as a raw image in the color type you want,
1186 | no matter whether the PNG was encoded with a palette, greyscale or RGBA color.
1187 | And if you encode an image, by default LodePNG will automatically choose the PNG
1188 | color type that gives good compression based on the values of colors and amount
1189 | of colors in the image. It can be configured to let you control it instead as
1190 | well, though.
1191 |
1192 | To be able to do this, LodePNG does conversions from one color mode to another.
1193 | It can convert from almost any color type to any other color type, except the
1194 | following conversions: RGB to greyscale is not supported, and converting to a
1195 | palette when the palette doesn't have a required color is not supported. This is
1196 | not supported on purpose: this is information loss which requires a color
1197 | reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey
1198 | is easy, but there are multiple ways if you want to give some channels more
1199 | weight).
1200 |
1201 | By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB
1202 | color, no matter what color type the PNG has. And by default when encoding,
1203 | LodePNG automatically picks the best color model for the output PNG, and expects
1204 | the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control
1205 | the color format of the images yourself, you can skip this chapter.
1206 |
1207 | 6.1. PNG color types
1208 | --------------------
1209 |
1210 | A PNG image can have many color types, ranging from 1-bit color to 64-bit color,
1211 | as well as palettized color modes. After the zlib decompression and unfiltering
1212 | in the PNG image is done, the raw pixel data will have that color type and thus
1213 | a certain amount of bits per pixel. If you want the output raw image after
1214 | decoding to have another color type, a conversion is done by LodePNG.
1215 |
1216 | The PNG specification gives the following color types:
1217 |
1218 | 0: greyscale, bit depths 1, 2, 4, 8, 16
1219 | 2: RGB, bit depths 8 and 16
1220 | 3: palette, bit depths 1, 2, 4 and 8
1221 | 4: greyscale with alpha, bit depths 8 and 16
1222 | 6: RGBA, bit depths 8 and 16
1223 |
1224 | Bit depth is the amount of bits per pixel per color channel. So the total amount
1225 | of bits per pixel is: amount of channels * bitdepth.
1226 |
1227 | 6.2. color conversions
1228 | ----------------------
1229 |
1230 | As explained in the sections about the encoder and decoder, you can specify
1231 | color types and bit depths in info_png and info_raw to change the default
1232 | behaviour.
1233 |
1234 | If, when decoding, you want the raw image to be something else than the default,
1235 | you need to set the color type and bit depth you want in the LodePNGColorMode,
1236 | or the parameters colortype and bitdepth of the simple decoding function.
1237 |
1238 | If, when encoding, you use another color type than the default in the raw input
1239 | image, you need to specify its color type and bit depth in the LodePNGColorMode
1240 | of the raw image, or use the parameters colortype and bitdepth of the simple
1241 | encoding function.
1242 |
1243 | If, when encoding, you don't want LodePNG to choose the output PNG color type
1244 | but control it yourself, you need to set auto_convert in the encoder settings
1245 | to false, and specify the color type you want in the LodePNGInfo of the
1246 | encoder (including palette: it can generate a palette if auto_convert is true,
1247 | otherwise not).
1248 |
1249 | If the input and output color type differ (whether user chosen or auto chosen),
1250 | LodePNG will do a color conversion, which follows the rules below, and may
1251 | sometimes result in an error.
1252 |
1253 | To avoid some confusion:
1254 | -the decoder converts from PNG to raw image
1255 | -the encoder converts from raw image to PNG
1256 | -the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image
1257 | -the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG
1258 | -when encoding, the color type in LodePNGInfo is ignored if auto_convert
1259 | is enabled, it is automatically generated instead
1260 | -when decoding, the color type in LodePNGInfo is set by the decoder to that of the original
1261 | PNG image, but it can be ignored since the raw image has the color type you requested instead
1262 | -if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion
1263 | between the color types is done if the color types are supported. If it is not
1264 | supported, an error is returned. If the types are the same, no conversion is done.
1265 | -even though some conversions aren't supported, LodePNG supports loading PNGs from any
1266 | colortype and saving PNGs to any colortype, sometimes it just requires preparing
1267 | the raw image correctly before encoding.
1268 | -both encoder and decoder use the same color converter.
1269 |
1270 | Non supported color conversions:
1271 | -color to greyscale: no error is thrown, but the result will look ugly because
1272 | only the red channel is taken
1273 | -anything to palette when that palette does not have that color in it: in this
1274 | case an error is thrown
1275 |
1276 | Supported color conversions:
1277 | -anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
1278 | -any grey or grey+alpha, to grey or grey+alpha
1279 | -anything to a palette, as long as the palette has the requested colors in it
1280 | -removing alpha channel
1281 | -higher to smaller bitdepth, and vice versa
1282 |
1283 | If you want no color conversion to be done (e.g. for speed or control):
1284 | -In the encoder, you can make it save a PNG with any color type by giving the
1285 | raw color mode and LodePNGInfo the same color mode, and setting auto_convert to
1286 | false.
1287 | -In the decoder, you can make it store the pixel data in the same color type
1288 | as the PNG has, by setting the color_convert setting to false. Settings in
1289 | info_raw are then ignored.
1290 |
1291 | The function lodepng_convert does the color conversion. It is available in the
1292 | interface but normally isn't needed since the encoder and decoder already call
1293 | it.
1294 |
1295 | 6.3. padding bits
1296 | -----------------
1297 |
1298 | In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines
1299 | have a bit amount that isn't a multiple of 8, then padding bits are used so that each
1300 | scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output.
1301 | The raw input image you give to the encoder, and the raw output image you get from the decoder
1302 | will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
1303 | of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte,
1304 | not the first bit of a new byte.
1305 |
1306 | 6.4. A note about 16-bits per channel and endianness
1307 | ----------------------------------------------------
1308 |
1309 | LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like
1310 | for any other color format. The 16-bit values are stored in big endian (most
1311 | significant byte first) in these arrays. This is the opposite order of the
1312 | little endian used by x86 CPU's.
1313 |
1314 | LodePNG always uses big endian because the PNG file format does so internally.
1315 | Conversions to other formats than PNG uses internally are not supported by
1316 | LodePNG on purpose, there are myriads of formats, including endianness of 16-bit
1317 | colors, the order in which you store R, G, B and A, and so on. Supporting and
1318 | converting to/from all that is outside the scope of LodePNG.
1319 |
1320 | This may mean that, depending on your use case, you may want to convert the big
1321 | endian output of LodePNG to little endian with a for loop. This is certainly not
1322 | always needed, many applications and libraries support big endian 16-bit colors
1323 | anyway, but it means you cannot simply cast the unsigned char* buffer to an
1324 | unsigned short* buffer on x86 CPUs.
1325 |
1326 |
1327 | 7. error values
1328 | ---------------
1329 |
1330 | All functions in LodePNG that return an error code, return 0 if everything went
1331 | OK, or a non-zero code if there was an error.
1332 |
1333 | The meaning of the LodePNG error values can be retrieved with the function
1334 | lodepng_error_text: given the numerical error code, it returns a description
1335 | of the error in English as a string.
1336 |
1337 | Check the implementation of lodepng_error_text to see the meaning of each code.
1338 |
1339 |
1340 | 8. chunks and PNG editing
1341 | -------------------------
1342 |
1343 | If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG
1344 | editor that should follow the rules about handling of unknown chunks, or if your
1345 | program is able to read other types of chunks than the ones handled by LodePNG,
1346 | then that's possible with the chunk functions of LodePNG.
1347 |
1348 | A PNG chunk has the following layout:
1349 |
1350 | 4 bytes length
1351 | 4 bytes type name
1352 | length bytes data
1353 | 4 bytes CRC
1354 |
1355 | 8.1. iterating through chunks
1356 | -----------------------------
1357 |
1358 | If you have a buffer containing the PNG image data, then the first chunk (the
1359 | IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the
1360 | signature of the PNG and are not part of a chunk. But if you start at byte 8
1361 | then you have a chunk, and can check the following things of it.
1362 |
1363 | NOTE: none of these functions check for memory buffer boundaries. To avoid
1364 | exploits, always make sure the buffer contains all the data of the chunks.
1365 | When using lodepng_chunk_next, make sure the returned value is within the
1366 | allocated memory.
1367 |
1368 | unsigned lodepng_chunk_length(const unsigned char* chunk):
1369 |
1370 | Get the length of the chunk's data. The total chunk length is this length + 12.
1371 |
1372 | void lodepng_chunk_type(char type[5], const unsigned char* chunk):
1373 | unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type):
1374 |
1375 | Get the type of the chunk or compare if it's a certain type
1376 |
1377 | unsigned char lodepng_chunk_critical(const unsigned char* chunk):
1378 | unsigned char lodepng_chunk_private(const unsigned char* chunk):
1379 | unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk):
1380 |
1381 | Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are).
1382 | Check if the chunk is private (public chunks are part of the standard, private ones not).
1383 | Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical
1384 | chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your
1385 | program doesn't handle that type of unknown chunk.
1386 |
1387 | unsigned char* lodepng_chunk_data(unsigned char* chunk):
1388 | const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk):
1389 |
1390 | Get a pointer to the start of the data of the chunk.
1391 |
1392 | unsigned lodepng_chunk_check_crc(const unsigned char* chunk):
1393 | void lodepng_chunk_generate_crc(unsigned char* chunk):
1394 |
1395 | Check if the crc is correct or generate a correct one.
1396 |
1397 | unsigned char* lodepng_chunk_next(unsigned char* chunk):
1398 | const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk):
1399 |
1400 | Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these
1401 | functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
1402 | data available in the buffer to be able to go to the next chunk.
1403 |
1404 | unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk):
1405 | unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
1406 | const char* type, const unsigned char* data):
1407 |
1408 | These functions are used to create new chunks that are appended to the data in *out that has
1409 | length *outlength. The append function appends an existing chunk to the new data. The create
1410 | function creates a new chunk with the given parameters and appends it. Type is the 4-letter
1411 | name of the chunk.
1412 |
1413 | 8.2. chunks in info_png
1414 | -----------------------
1415 |
1416 | The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3
1417 | buffers (each with size) to contain 3 types of unknown chunks:
1418 | the ones that come before the PLTE chunk, the ones that come between the PLTE
1419 | and the IDAT chunks, and the ones that come after the IDAT chunks.
1420 | It's necessary to make the distionction between these 3 cases because the PNG
1421 | standard forces to keep the ordering of unknown chunks compared to the critical
1422 | chunks, but does not force any other ordering rules.
1423 |
1424 | info_png.unknown_chunks_data[0] is the chunks before PLTE
1425 | info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT
1426 | info_png.unknown_chunks_data[2] is the chunks after IDAT
1427 |
1428 | The chunks in these 3 buffers can be iterated through and read by using the same
1429 | way described in the previous subchapter.
1430 |
1431 | When using the decoder to decode a PNG, you can make it store all unknown chunks
1432 | if you set the option settings.remember_unknown_chunks to 1. By default, this
1433 | option is off (0).
1434 |
1435 | The encoder will always encode unknown chunks that are stored in the info_png.
1436 | If you need it to add a particular chunk that isn't known by LodePNG, you can
1437 | use lodepng_chunk_append or lodepng_chunk_create to the chunk data in
1438 | info_png.unknown_chunks_data[x].
1439 |
1440 | Chunks that are known by LodePNG should not be added in that way. E.g. to make
1441 | LodePNG add a bKGD chunk, set background_defined to true and add the correct
1442 | parameters there instead.
1443 |
1444 |
1445 | 9. compiler support
1446 | -------------------
1447 |
1448 | No libraries other than the current standard C library are needed to compile
1449 | LodePNG. For the C++ version, only the standard C++ library is needed on top.
1450 | Add the files lodepng.c(pp) and lodepng.h to your project, include
1451 | lodepng.h where needed, and your program can read/write PNG files.
1452 |
1453 | It is compatible with C90 and up, and C++03 and up.
1454 |
1455 | If performance is important, use optimization when compiling! For both the
1456 | encoder and decoder, this makes a large difference.
1457 |
1458 | Make sure that LodePNG is compiled with the same compiler of the same version
1459 | and with the same settings as the rest of the program, or the interfaces with
1460 | std::vectors and std::strings in C++ can be incompatible.
1461 |
1462 | CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets.
1463 |
1464 | *) gcc and g++
1465 |
1466 | LodePNG is developed in gcc so this compiler is natively supported. It gives no
1467 | warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
1468 | version 4.7.1 on Linux, 32-bit and 64-bit.
1469 |
1470 | *) Clang
1471 |
1472 | Fully supported and warning-free.
1473 |
1474 | *) Mingw
1475 |
1476 | The Mingw compiler (a port of gcc for Windows) should be fully supported by
1477 | LodePNG.
1478 |
1479 | *) Visual Studio and Visual C++ Express Edition
1480 |
1481 | LodePNG should be warning-free with warning level W4. Two warnings were disabled
1482 | with pragmas though: warning 4244 about implicit conversions, and warning 4996
1483 | where it wants to use a non-standard function fopen_s instead of the standard C
1484 | fopen.
1485 |
1486 | Visual Studio may want "stdafx.h" files to be included in each source file and
1487 | give an error "unexpected end of file while looking for precompiled header".
1488 | This is not standard C++ and will not be added to the stock LodePNG. You can
1489 | disable it for lodepng.cpp only by right clicking it, Properties, C/C++,
1490 | Precompiled Headers, and set it to Not Using Precompiled Headers there.
1491 |
1492 | NOTE: Modern versions of VS should be fully supported, but old versions, e.g.
1493 | VS6, are not guaranteed to work.
1494 |
1495 | *) Compilers on Macintosh
1496 |
1497 | LodePNG has been reported to work both with gcc and LLVM for Macintosh, both for
1498 | C and C++.
1499 |
1500 | *) Other Compilers
1501 |
1502 | If you encounter problems on any compilers, feel free to let me know and I may
1503 | try to fix it if the compiler is modern and standards complient.
1504 |
1505 |
1506 | 10. examples
1507 | ------------
1508 |
1509 | This decoder example shows the most basic usage of LodePNG. More complex
1510 | examples can be found on the LodePNG website.
1511 |
1512 | 10.1. decoder C++ example
1513 | -------------------------
1514 |
1515 | #include "lodepng.h"
1516 | #include
1517 |
1518 | int main(int argc, char *argv[])
1519 | {
1520 | const char* filename = argc > 1 ? argv[1] : "test.png";
1521 |
1522 | //load and decode
1523 | std::vector image;
1524 | unsigned width, height;
1525 | unsigned error = lodepng::decode(image, width, height, filename);
1526 |
1527 | //if there's an error, display it
1528 | if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;
1529 |
1530 | //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
1531 | }
1532 |
1533 | 10.2. decoder C example
1534 | -----------------------
1535 |
1536 | #include "lodepng.h"
1537 |
1538 | int main(int argc, char *argv[])
1539 | {
1540 | unsigned error;
1541 | unsigned char* image;
1542 | size_t width, height;
1543 | const char* filename = argc > 1 ? argv[1] : "test.png";
1544 |
1545 | error = lodepng_decode32_file(&image, &width, &height, filename);
1546 |
1547 | if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error));
1548 |
1549 | / * use image here * /
1550 |
1551 | free(image);
1552 | return 0;
1553 | }
1554 |
1555 |
1556 | 11. changes
1557 | -----------
1558 |
1559 | The version number of LodePNG is the date of the change given in the format
1560 | yyyymmdd.
1561 |
1562 | Some changes aren't backwards compatible. Those are indicated with a (!)
1563 | symbol.
1564 |
1565 | *) 23 aug 2014: Reduced needless memory usage of decoder.
1566 | *) 28 jun 2014: Removed fix_png setting, always support palette OOB for
1567 | simplicity. Made ColorProfile public.
1568 | *) 09 jun 2014: Faster encoder by fixing hash bug and more zeros optimization.
1569 | *) 22 dec 2013: Power of two windowsize required for optimization.
1570 | *) 15 apr 2013: Fixed bug with LAC_ALPHA and color key.
1571 | *) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png).
1572 | *) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_"
1573 | prefix for the custom allocators and made it possible with a new #define to
1574 | use custom ones in your project without needing to change lodepng's code.
1575 | *) 28 jan 2013: Bugfix with color key.
1576 | *) 27 okt 2012: Tweaks in text chunk keyword length error handling.
1577 | *) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode.
1578 | (no palette). Better deflate tree encoding. New compression tweak settings.
1579 | Faster color conversions while decoding. Some internal cleanups.
1580 | *) 23 sep 2012: Reduced warnings in Visual Studio a little bit.
1581 | *) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions
1582 | and made it work with function pointers instead.
1583 | *) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc
1584 | and free functions and toggle #defines from compiler flags. Small fixes.
1585 | *) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible.
1586 | *) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed
1587 | redundant C++ codec classes. Reduced amount of structs. Everything changed,
1588 | but it is cleaner now imho and functionality remains the same. Also fixed
1589 | several bugs and shrinked the implementation code. Made new samples.
1590 | *) 6 nov 2011 (!): By default, the encoder now automatically chooses the best
1591 | PNG color model and bit depth, based on the amount and type of colors of the
1592 | raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color.
1593 | *) 9 okt 2011: simpler hash chain implementation for the encoder.
1594 | *) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching.
1595 | *) 23 aug 2011: tweaked the zlib compression parameters after benchmarking.
1596 | A bug with the PNG filtertype heuristic was fixed, so that it chooses much
1597 | better ones (it's quite significant). A setting to do an experimental, slow,
1598 | brute force search for PNG filter types is added.
1599 | *) 17 aug 2011 (!): changed some C zlib related function names.
1600 | *) 16 aug 2011: made the code less wide (max 120 characters per line).
1601 | *) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
1602 | *) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
1603 | *) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman
1604 | to optimize long sequences of zeros.
1605 | *) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and
1606 | LodePNG_InfoColor_canHaveAlpha functions for convenience.
1607 | *) 7 nov 2010: added LodePNG_error_text function to get error code description.
1608 | *) 30 okt 2010: made decoding slightly faster
1609 | *) 26 okt 2010: (!) changed some C function and struct names (more consistent).
1610 | Reorganized the documentation and the declaration order in the header.
1611 | *) 08 aug 2010: only changed some comments and external samples.
1612 | *) 05 jul 2010: fixed bug thanks to warnings in the new gcc version.
1613 | *) 14 mar 2010: fixed bug where too much memory was allocated for char buffers.
1614 | *) 02 sep 2008: fixed bug where it could create empty tree that linux apps could
1615 | read by ignoring the problem but windows apps couldn't.
1616 | *) 06 jun 2008: added more error checks for out of memory cases.
1617 | *) 26 apr 2008: added a few more checks here and there to ensure more safety.
1618 | *) 06 mar 2008: crash with encoding of strings fixed
1619 | *) 02 feb 2008: support for international text chunks added (iTXt)
1620 | *) 23 jan 2008: small cleanups, and #defines to divide code in sections
1621 | *) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
1622 | *) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
1623 | *) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
1624 | Also vareous fixes, such as in the deflate and the padding bits code.
1625 | *) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
1626 | filtering code of encoder.
1627 | *) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
1628 | C++ wrapper around this provides an interface almost identical to before.
1629 | Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code
1630 | are together in these files but it works both for C and C++ compilers.
1631 | *) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks
1632 | *) 30 aug 2007: bug fixed which makes this Borland C++ compatible
1633 | *) 09 aug 2007: some VS2005 warnings removed again
1634 | *) 21 jul 2007: deflate code placed in new namespace separate from zlib code
1635 | *) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images
1636 | *) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing
1637 | invalid std::vector element [0] fixed, and level 3 and 4 warnings removed
1638 | *) 02 jun 2007: made the encoder add a tag with version by default
1639 | *) 27 may 2007: zlib and png code separated (but still in the same file),
1640 | simple encoder/decoder functions added for more simple usage cases
1641 | *) 19 may 2007: minor fixes, some code cleaning, new error added (error 69),
1642 | moved some examples from here to lodepng_examples.cpp
1643 | *) 12 may 2007: palette decoding bug fixed
1644 | *) 24 apr 2007: changed the license from BSD to the zlib license
1645 | *) 11 mar 2007: very simple addition: ability to encode bKGD chunks.
1646 | *) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding
1647 | palettized PNG images. Plus little interface change with palette and texts.
1648 | *) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes.
1649 | Fixed a bug where the end code of a block had length 0 in the Huffman tree.
1650 | *) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented
1651 | and supported by the encoder, resulting in smaller PNGs at the output.
1652 | *) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone.
1653 | *) 24 jan 2007: gave encoder an error interface. Added color conversion from any
1654 | greyscale type to 8-bit greyscale with or without alpha.
1655 | *) 21 jan 2007: (!) Totally changed the interface. It allows more color types
1656 | to convert to and is more uniform. See the manual for how it works now.
1657 | *) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days:
1658 | encode/decode custom tEXt chunks, separate classes for zlib & deflate, and
1659 | at last made the decoder give errors for incorrect Adler32 or Crc.
1660 | *) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel.
1661 | *) 29 dec 2006: Added support for encoding images without alpha channel, and
1662 | cleaned out code as well as making certain parts faster.
1663 | *) 28 dec 2006: Added "Settings" to the encoder.
1664 | *) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
1665 | Removed some code duplication in the decoder. Fixed little bug in an example.
1666 | *) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
1667 | Fixed a bug of the decoder with 16-bit per color.
1668 | *) 15 okt 2006: Changed documentation structure
1669 | *) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
1670 | given image buffer, however for now it's not compressed.
1671 | *) 08 sep 2006: (!) Changed to interface with a Decoder class
1672 | *) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
1673 | way. Renamed decodePNG to decodePNGGeneric.
1674 | *) 29 jul 2006: (!) Changed the interface: image info is now returned as a
1675 | struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
1676 | *) 28 jul 2006: Cleaned the code and added new error checks.
1677 | Corrected terminology "deflate" into "inflate".
1678 | *) 23 jun 2006: Added SDL example in the documentation in the header, this
1679 | example allows easy debugging by displaying the PNG and its transparency.
1680 | *) 22 jun 2006: (!) Changed way to obtain error value. Added
1681 | loadFile function for convenience. Made decodePNG32 faster.
1682 | *) 21 jun 2006: (!) Changed type of info vector to unsigned.
1683 | Changed position of palette in info vector. Fixed an important bug that
1684 | happened on PNGs with an uncompressed block.
1685 | *) 16 jun 2006: Internally changed unsigned into unsigned where
1686 | needed, and performed some optimizations.
1687 | *) 07 jun 2006: (!) Renamed functions to decodePNG and placed them
1688 | in LodePNG namespace. Changed the order of the parameters. Rewrote the
1689 | documentation in the header. Renamed files to lodepng.cpp and lodepng.h
1690 | *) 22 apr 2006: Optimized and improved some code
1691 | *) 07 sep 2005: (!) Changed to std::vector interface
1692 | *) 12 aug 2005: Initial release (C++, decoder only)
1693 |
1694 |
1695 | 12. contact information
1696 | -----------------------
1697 |
1698 | Feel free to contact me with suggestions, problems, comments, ... concerning
1699 | LodePNG. If you encounter a PNG image that doesn't work properly with this
1700 | decoder, feel free to send it and I'll use it to find and fix the problem.
1701 |
1702 | My email address is (puzzle the account and domain together with an @ symbol):
1703 | Domain: gmail dot com.
1704 | Account: lode dot vandevenne.
1705 |
1706 |
1707 | Copyright (c) 2005-2014 Lode Vandevenne
1708 | */
1709 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSArray.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include "FSObject.h"
4 | #include "FSArray.h"
5 |
6 | FSArray *FSArray_alloc(int length)
7 | {
8 | FSArray *p = (FSArray *) malloc(sizeof(FSArray));
9 | p->array = (void**) malloc(length*sizeof(void*));
10 | p->cursor = 0;
11 | p->length = length;
12 | p->retainCount = 1;
13 | p->type = "Array";
14 | return p;
15 | }
16 |
17 | int FSArray_count(FSArray *p){
18 | return p->length;
19 | }
20 |
21 | void *FSArray_objectAtIndex(FSArray *p,int index){
22 | return p->array[index];
23 | }
24 |
25 | void FSArray_append(FSArray *p,void *elem){
26 | FSObject_retain(elem);
27 | p->array[p->cursor] = elem;
28 | p->cursor ++;
29 | }
30 |
31 | void FSArray_release(FSArray *p){
32 | int i = 0;
33 | for(i=0; i < p->length; i++){
34 | void *elem = (void*)p->array[i];
35 | FSObject_release(elem);
36 | }
37 | p->retainCount --;
38 | if(p->retainCount == 0){
39 | free(p->array);
40 | free(p);
41 | }
42 | }
43 |
44 | void FSArray_retain(FSArray *p){
45 | FSObject_retain(p);
46 | }
47 |
48 |
49 |
50 |
51 |
52 |
53 |
54 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSArray.h:
--------------------------------------------------------------------------------
1 | //class FSArray//
2 |
3 | #ifndef FSARRAY_H
4 | #define FSARRAY_H
5 |
6 | typedef struct FSArray{
7 | int retainCount;
8 | char *type;
9 | int cursor;
10 | int length;
11 | void** array;
12 | }FSArray;
13 |
14 | FSArray *FSArray_alloc(int length);
15 | void FSArray_append(FSArray *p, void *elem);
16 | void FSArray_release(FSArray *p);
17 | void FSArray_retain(FSArray *p);
18 | int FSArray_count(FSArray *p);
19 | void *FSArray_objectAtIndex(FSArray *p,int index);
20 |
21 | #endif
22 |
23 |
24 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSNumber.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include
4 | #include "FSObject.h"
5 | #include "FSNumber.h"
6 |
7 | FSNumber *FSNumber_allocWithInt(int intval){
8 | FSNumber *n = (FSNumber *) malloc(sizeof(FSNumber));
9 | n->intValue = intval;
10 | n->floatValue = (float)intval;
11 | n->retainCount = 1;
12 | n->type = "Number";
13 | return n;
14 | }
15 |
16 | FSNumber *FSNumber_allocWithFloat(float floatval){
17 | FSNumber *n = (FSNumber *) malloc(sizeof(FSNumber));
18 | n->intValue = (int)round(floatval);
19 | n->floatValue = floatval;
20 | n->retainCount = 1;
21 | n->type = "Number";
22 | return n;
23 | }
24 |
25 | void FSNumber_release(FSNumber *n){
26 | FSObject_release(n);
27 | }
28 |
29 | void FSNumber_retain(FSNumber *n){
30 | FSObject_retain(n);
31 | }
32 |
33 |
34 |
35 |
36 |
37 |
38 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSNumber.h:
--------------------------------------------------------------------------------
1 | //class FSNumber//
2 |
3 | #ifndef FSNUMBER_H
4 | #define FSNUMBER_H
5 |
6 | typedef struct FSNumber{
7 | int retainCount;
8 | char *type;
9 | float floatValue;
10 | float intValue;
11 | }FSNumber;
12 |
13 | FSNumber *FSNumber_allocWithInt(int intval);
14 | FSNumber *FSNumber_allocWithFloat(float floatval);
15 | void FSNumber_release(FSNumber *p);
16 | void FSNumber_retain(FSNumber *p);
17 |
18 | #endif
19 |
20 |
21 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSObject.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include "FSObject.h"
4 |
5 | void FSObject_release(void *o){
6 | FSObject *obj = (FSObject*)o;
7 | obj->retainCount --;
8 | if(obj->retainCount == 0){
9 | free(obj);
10 | }
11 | }
12 |
13 | void FSObject_retain(void *o){
14 | FSObject *obj = (FSObject*)o;
15 | obj->retainCount ++;
16 | }
17 |
--------------------------------------------------------------------------------
/src/lib/sketchy/FSObject.h:
--------------------------------------------------------------------------------
1 | //class FSObject//
2 |
3 | #ifndef FSOBJECT_H
4 | #define FSOBJECT_H
5 |
6 | typedef struct FSObject{
7 | int retainCount;
8 | char *type;
9 | }FSObject;
10 |
11 | void FSObject_release(void *o);
12 | void FSObject_retain(void *o);
13 |
14 | #endif
15 |
16 |
17 |
--------------------------------------------------------------------------------
/src/lib/sketchy/Point.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include
4 | #include "Point.h"
5 | #include "FSObject.h"
6 | #include "FSArray.h"
7 | #include "FSNumber.h"
8 |
9 | Point *Point_alloc(float x, float y){
10 | Point *p = (Point *) malloc(sizeof(Point));
11 | p->x = x;
12 | p->y = y;
13 | p->retainCount = 1;
14 | p->type = "Point";
15 | return p;
16 | }
17 |
18 | void Point_copy(Point *src,Point *dest){
19 | dest->x = src->x;
20 | dest->y = src->y;
21 | dest->left_angle = src->left_angle;
22 | dest->right_angle = src->right_angle;
23 | dest->left_steps = src->left_steps;
24 | dest->right_steps = src->right_steps;
25 | }
26 |
27 | void Point_log(Point *p){
28 | printf("Point <%p left:%i l-angle:%f right:%i r-angle:%f - x:%f y:%f >\n",
29 | p,p->left_steps,p->left_angle,p->right_steps,p->right_angle,p->x,p->y);
30 | }
31 |
32 | void Point_release(Point *p){
33 | FSObject_release(p);
34 | }
35 |
36 | void Point_retain(Point *p){
37 | FSObject_retain(p);
38 | }
39 |
40 | void Point_setNull(Point *p){
41 | p->x = 0.0;
42 | p->y = 0.0;
43 | }
44 |
45 |
46 |
47 |
--------------------------------------------------------------------------------
/src/lib/sketchy/Point.h:
--------------------------------------------------------------------------------
1 | //class Point//
2 |
3 | #ifndef POINT_H
4 | #define POINT_H
5 |
6 | typedef struct FSPoint{
7 | int retainCount;
8 | char *type;
9 | float x;
10 | float y;
11 | float left_angle;
12 | float right_angle;
13 | int left_steps;
14 | int right_steps;
15 | }Point;
16 |
17 | Point *Point_alloc(float x, float y);
18 |
19 | Point *Point_allocWithXY(float x, float y);
20 | void Point_updateWithXY(Point *p,float x, float y);
21 |
22 | Point *Point_allocWithSteps(int left_steps, int right_steps);
23 | void Point_updateWithSteps(Point *p,int left_steps, int right_steps);
24 |
25 | void Point_copy(Point *src,Point *dest);
26 | void Point_release(Point *p);
27 | void Point_retain(Point *p);
28 | void Point_setNull(Point *p);
29 | void Point_log(Point *p);
30 |
31 | #endif
32 |
33 |
34 |
--------------------------------------------------------------------------------
/src/lib/sketchy/SketchyImage.c:
--------------------------------------------------------------------------------
1 | #include
2 | #include
3 | #include
4 | #include
5 |
6 | #include "FSObject.h"
7 | #include "Point.h"
8 | #include "bool.h"
9 | #include "SketchyImage.h"
10 |
11 | #include "../lodepng/lodepng.h"
12 |
13 | typedef enum{
14 | lineDarknessModeAvg = 1,
15 | lineDarknessModeClear = 2
16 | }LineDarknessMode;
17 |
18 | int gCounter = 0;
19 |
20 | int SketchyImage_kernelValueByXY(SketchyImage *obj,int x, int y, bool clear,int kernelSize);
21 |
22 | SketchyImage *SketchyImage_allocWithFileName(const char *filename){
23 |
24 | SketchyImage *obj = (SketchyImage *) malloc(sizeof(SketchyImage));
25 | obj->retainCount = 1;
26 | obj->type = "SketchyImage";
27 | obj->scaleFactor = 1.0;
28 | obj->xCorrection = 0.0;
29 | obj->yCorrection = 0.0;
30 | obj->xOffset = 0.0;
31 | obj->yOffset = 0.0;
32 | obj->brightness = 0;
33 | obj->outputBrightness = 0;
34 | obj->nibsize = 1;
35 | obj->avgBrightness = 255.0;
36 |
37 | unsigned error;
38 | unsigned char* image;
39 | unsigned width, height;
40 |
41 | error = lodepng_decode32_file(&image, &width, &height, filename);
42 | if(error){
43 | printf("error %u: %s\n", error, lodepng_error_text(error));
44 | }
45 |
46 | obj->width = width;
47 | obj->height = height;
48 |
49 | int numPixels = obj->width * obj->height;
50 |
51 | obj->imageData = (unsigned char*)calloc(numPixels , 1);
52 | obj->outputImageData = (unsigned char*)calloc(numPixels , 1);
53 |
54 | if(obj->imageData == NULL || obj->outputImageData == NULL){
55 | printf("mem error\n");
56 | }
57 |
58 | int i;
59 | int j;
60 | int numpix = width*height*4;
61 | for(i=0,j=0; ibrightness += pixelValue;
64 | obj->outputImageData[j] = 255;
65 | obj->imageData[j] = pixelValue;
66 | }
67 | obj->outputBrightness = width*height * 255;
68 | obj->avgBrightness = obj->brightness / (width*height);
69 |
70 | free(image);
71 |
72 | return obj;
73 |
74 | }
75 |
76 | int SketchyImage_getCanvasWidth(SketchyImage *obj){
77 | return obj->width;
78 | }
79 |
80 | int SketchyImage_getCanvasHeight(SketchyImage *obj){
81 | return obj->height;
82 | }
83 |
84 | void SketchyImage_setNibSize(SketchyImage *obj,int nibsize){
85 | obj->nibsize = nibsize;
86 | }
87 |
88 | long int SketchyImage_getOutputBrightness(SketchyImage *obj){
89 | return obj->outputBrightness;
90 | }
91 |
92 | long int SketchyImage_getBrightness(SketchyImage *obj){
93 | return obj->brightness;
94 | }
95 |
96 | float SketchyImage_getAvgBrightness(SketchyImage *obj){
97 | return obj->avgBrightness;
98 | }
99 |
100 | Point *SketchyImage_getDarkPixel(SketchyImage *obj){
101 | int darkest = 255;
102 | int i = 0;
103 | int x = 0;
104 | int y = 0;
105 | int numPixels = obj->width * obj->height;
106 | for (i=0; iimageData[i];
108 | if(pixelValue < darkest){
109 | darkest = pixelValue;
110 | x = i%obj->width;
111 | y = floor(i/obj->width);
112 | }
113 | }
114 | return Point_alloc((float)x,(float)y);
115 | }
116 |
117 | void SketchyImage_release(SketchyImage *obj){
118 | obj->retainCount --;
119 | if(obj->retainCount == 0){
120 | free(obj->imageData);
121 | free(obj);
122 | }
123 | }
124 |
125 | void SketchyImage_retain(SketchyImage *obj){
126 | FSObject_retain(obj);
127 | }
128 |
129 | //
130 | // helper method called by :
131 | // 1) SketchyImage_avgDarknessForLine returns the average darkness for pixels under a line
132 | // 2) SketchyImage_clearDarknessForLine clears the darkness for pixels under the line, returns 0
133 | //
134 | float SketchyImage_darknessHelperForLine(SketchyImage *obj, float x1, float y1, float x2, float y2,LineDarknessMode mode){
135 |
136 | int kernelSize = obj->nibsize;
137 | if(kernelSize%2 == 0){
138 | kernelSize = kernelSize - 1;
139 | }
140 |
141 | int xpol = (x1-x2) < 0;
142 | int ypol = (y1-y2) < 0;
143 | if(xpol == 0){
144 | xpol = -1;
145 | }
146 | if(ypol == 0){
147 | ypol = -1;
148 | }
149 |
150 | float xd = fabs(x1-x2);
151 | float yd = fabs(y1-y2);
152 | float slope = (x1-x2)/(y1-y2);
153 | float totaldarkness = 0;
154 | float avg;
155 | if(xd > yd){
156 | int i;
157 | int cx = (int)x1;
158 | int cy = (int)y1;
159 | for(i=0;iscaleFactor;
201 | y = y * obj->scaleFactor;
202 |
203 | float degree_to_radian_fact = 0.0174532925;
204 | int n = 360; //full circle scan
205 | int i;
206 | float best = 9999.0;
207 | int bestX = 0;
208 | int bestY = 0;
209 | gCounter ++;
210 | for(i=gCounter; iwidth-1 && ry < obj->height-1 && rx > 0 && ry > 0){
216 | float avg = SketchyImage_avgDarknessForLine(obj,x,y,rx,ry);
217 | if(avg < best){
218 | best = avg;
219 | bestX = rx;
220 | bestY = ry;
221 | // if(avg < 100){
222 | // break;
223 | // }
224 | }
225 | }
226 |
227 | }
228 | SketchyImage_clearDarknessForLine(obj,x,y,bestX,bestY);
229 | bestX = bestX/obj->scaleFactor;
230 | bestY = bestY/obj->scaleFactor;
231 | return Point_alloc((float)bestX,(float)bestY);
232 |
233 | }
234 |
235 | int pix(SketchyImage *obj,int pixelindex){
236 | if(pixelindex < (obj->width * obj->height)){
237 | return pixelindex;
238 | }
239 | return 0;
240 | }
241 |
242 | int SketchyImage_getPixel(SketchyImage *obj,int x, int y){
243 | if (y < 0 || y > obj->height-1 || x < 0 || x > obj->width-1){
244 | return 255;
245 | }
246 | int index = y * obj->width + x;
247 | return obj->imageData[pix(obj,index)];
248 | }
249 |
250 | int SketchyImage_kernelValueByXY(SketchyImage *obj,int x, int y, bool clear,int kernelSize){
251 |
252 | //the image data contains a 6 byte header
253 | //these are the threshold levels
254 | //this used to be fixed (36 spacing)
255 | //int levels[6] = {217, 180, 144, 108, 72, 36};
256 | if (x > obj->width-1 || y > obj->height-1 || x < 0 || y < 0){
257 | //out of bounds
258 | return -1;
259 | }
260 | int w = obj->width;
261 | int pixelindex = y*w + x;
262 |
263 | int pixelValue = obj->imageData[pixelindex];
264 | if(kernelSize > 1){
265 | int i;
266 | int limit = (kernelSize - 1) / 2.0;
267 | for(i=0;iimageData[pix(obj,pixelindex+1+i)];
269 | pixelValue += obj->imageData[pix(obj,pixelindex+obj->width+(i*obj->width))];
270 | pixelValue += obj->imageData[pix(obj,pixelindex-obj->width-(i*obj->width))];
271 | pixelValue += obj->imageData[pix(obj,pixelindex-1-i)];
272 | }
273 | }
274 |
275 | if(clear){
276 | int index;
277 | if(kernelSize > 1){
278 | int i;
279 | int limit = (kernelSize - 1) / 2.0;
280 | for(i=0;ibrightness += (255-obj->imageData[index]);
284 | obj->imageData[index] = 255;
285 | obj->outputBrightness -= obj->outputImageData[index];
286 | obj->outputImageData[index] = 0;
287 |
288 | index = pix(obj,pixelindex+obj->width+(i*obj->width));
289 | obj->brightness += (255-obj->imageData[index]);
290 | obj->imageData[index] = 255;
291 | obj->outputBrightness -= obj->outputImageData[index];
292 | obj->outputImageData[index] = 0;
293 |
294 | index = pix(obj,pixelindex-obj->width-(i*obj->width));
295 | obj->brightness += (255-obj->imageData[index]);
296 | obj->imageData[index] = 255;
297 | obj->outputBrightness -= obj->outputImageData[index];
298 | obj->outputImageData[index] = 0;
299 |
300 | index = pix(obj,pixelindex-1-i);
301 | obj->brightness += (255-obj->imageData[index]);
302 | obj->imageData[index] = 255;
303 | obj->outputBrightness -= obj->outputImageData[index];
304 | obj->outputImageData[index] = 0;
305 |
306 | }
307 | }
308 | index = pixelindex;
309 | obj->brightness += (255-obj->imageData[index]);
310 | obj->imageData[index] = 255;
311 | obj->outputBrightness -= obj->outputImageData[index];
312 | obj->outputImageData[index] = 0;
313 | }
314 |
315 | return pixelValue;
316 | }
317 |
318 | void SketchyImage_saveStateAsPNG(SketchyImage *obj,const char *name){
319 | unsigned char *imd = obj->imageData;
320 | unsigned error = lodepng_encode_file(name, imd,obj->width, obj->height,LCT_GREY,8);
321 | if(error) printf("error %u: %s\n", error, lodepng_error_text(error));
322 | }
323 |
324 | void SketchyImage_saveAsPNG(SketchyImage *obj,const char *name){
325 | unsigned char *imdo = obj->outputImageData;
326 | unsigned erroro = lodepng_encode_file(name, imdo,obj->width, obj->height,LCT_GREY,8);
327 | if(erroro) printf("error %u: %s\n", erroro, lodepng_error_text(erroro));
328 | }
329 |
330 |
331 |
332 |
333 |
--------------------------------------------------------------------------------
/src/lib/sketchy/SketchyImage.h:
--------------------------------------------------------------------------------
1 | #ifndef SKETCHYIMAGE_H
2 | #define SKETCHYIMAGE_H
3 |
4 | #include "bool.h"
5 | #include "Point.h"
6 |
7 | typedef struct SketchyImage{
8 | int retainCount;
9 | char *type;
10 | unsigned char *imageData;
11 | unsigned char *outputImageData;
12 | float scaleFactor;
13 | float xCorrection;
14 | float yCorrection;
15 | float xOffset;
16 | float yOffset;
17 | long int brightness;
18 | long int outputBrightness;
19 | float avgBrightness;
20 | unsigned width;
21 | unsigned height;
22 | int nibsize;
23 | }SketchyImage;
24 |
25 | SketchyImage *SketchyImage_allocWithFileName(const char *filename);
26 | void SketchyImage_setNibSize(SketchyImage *obj,int nibsize);
27 | void SketchyImage_release(SketchyImage *obj);
28 | void SketchyImage_retain(SketchyImage *obj);
29 | void SketchyImage_saveAsPNG(SketchyImage *obj,const char *name);
30 | void SketchyImage_saveStateAsPNG(SketchyImage *obj,const char *name);
31 | float SketchyImage_avgDarknessForLine(SketchyImage *obj, float x1, float y1, float x2, float y2);
32 | Point *SketchyImage_bestPointOfNDestinationsFromXY2(SketchyImage *obj, int radius, int x, int y);
33 | long int SketchyImage_getBrightness(SketchyImage *obj);
34 | long int SketchyImage_getOutputBrightness(SketchyImage *obj);
35 | int SketchyImage_getCanvasWidth(SketchyImage *obj);
36 | int SketchyImage_getCanvasHeight(SketchyImage *obj);
37 | int SketchyImage_getPixel(SketchyImage *obj,int x, int y);
38 | Point *SketchyImage_getDarkPixel(SketchyImage *obj);
39 | float SketchyImage_getAvgBrightness(SketchyImage *obj);
40 |
41 | #endif
42 |
--------------------------------------------------------------------------------
/src/lib/sketchy/bool.h:
--------------------------------------------------------------------------------
1 | #ifndef BOOL_H
2 | #define BOOL_H
3 |
4 | typedef enum { false, true } bool;
5 |
6 | #endif
7 |
8 |
9 |
--------------------------------------------------------------------------------
/src/setup.py:
--------------------------------------------------------------------------------
1 | from distutils.core import setup, Extension
2 |
3 | module1 = Extension('blackstripes.sketchy', sources =
4 | ['blackstripes/sketchy.c',
5 | 'lib/lodepng/lodepng.c',
6 | 'lib/sketchy/SketchyImage.c',
7 | 'lib/sketchy/FSObject.c',
8 | 'lib/sketchy/Point.c',
9 | 'lib/sketchy/FSArray.c',
10 | 'lib/sketchy/FSNumber.c'])
11 |
12 | module2 = Extension('blackstripes.crossed', sources =
13 | ['blackstripes/crossed.c',
14 | 'lib/lodepng/lodepng.c',
15 | 'lib/sketchy/SketchyImage.c',
16 | 'lib/sketchy/FSObject.c',
17 | 'lib/sketchy/Point.c',
18 | 'lib/sketchy/FSArray.c',
19 | 'lib/sketchy/FSNumber.c'])
20 |
21 | module3 = Extension('blackstripes.spiral', sources =
22 | ['blackstripes/spiral.c',
23 | 'lib/lodepng/lodepng.c',
24 | 'lib/sketchy/SketchyImage.c',
25 | 'lib/sketchy/FSObject.c',
26 | 'lib/sketchy/Point.c',
27 | 'lib/sketchy/FSArray.c',
28 | 'lib/sketchy/FSNumber.c'])
29 |
30 | setup (name = 'blackstripes',
31 | version = '1.0',
32 | description = 'This is the blackstripes package',
33 | ext_modules = [module1, module2, module3],
34 | scripts=['cli/blackstripes'],
35 | packages=['blackstripes'],
36 | package_dir={'blackstripes': 'blackstripes'},
37 | )
38 |
--------------------------------------------------------------------------------
/test/ali.png:
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https://raw.githubusercontent.com/fullscreennl/blackstripes-python-extensions/366d3899b79daad5b6c5332a0ec63201374e46e4/test/ali.png
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/test/crossed-test.py:
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1 | from blackstripes import crossed
2 | from blackstripes import sketchy
3 | from blackstripes import spiral
4 | from PIL import Image
5 |
6 | def levels_by_preview_name(name):
7 | return (100, 150, 200, 230)
8 |
9 | def crop_by_preview_name(name):
10 | return name
11 |
12 | def classic_small(image_path, path, color):
13 |
14 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
15 | selected_crop = crop_by_preview_name(image_path)
16 |
17 | im = Image.open(selected_crop)
18 | im = im.resize((500,500), Image.ANTIALIAS)
19 | im.save(selected_crop)
20 |
21 | crossed.draw(selected_crop, # input
22 | path, # output
23 | 3, # nibsize (line size in output svg)
24 | color, # line color
25 | 1.00, # scaling factor
26 | l1, l2, l3, l4, # levels
27 | 1, # type
28 | 380,500,0.2 # signature transform
29 | )
30 |
31 |
32 | def sketchy_small(image_path, path, color):
33 |
34 | im = Image.open(image_path)
35 | im = im.resize((500,500), Image.ANTIALIAS)
36 | im.save(image_path)
37 |
38 | sketchy.draw(image_path, # input
39 | path, # output
40 | 2, # nibsize (line size in output svg)
41 | 100, # max line length
42 | color, # line color
43 | 1.00, # scaling factor
44 | 1, # line size (internal line size for calculations)
45 | 380,500,0.2 # signature transform
46 | )
47 |
48 |
49 | def spiral_small(image_path, path, color):
50 |
51 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
52 | selected_crop = crop_by_preview_name(image_path)
53 |
54 | im = Image.open(selected_crop)
55 | im = im.resize((500,500), Image.ANTIALIAS)
56 | im.save(selected_crop)
57 |
58 | spiral.draw(selected_crop, # input
59 | path, # output
60 | 4, # nibsize (line size in output svg)
61 | color, # line color
62 | 1.00, # scaling factor
63 | l1, l2, l3, l4, # levels
64 | 3, # line spacing
65 | 380,500,0.2 # signature transform
66 | )
67 |
68 | def classic_large(image_path, path, color):
69 |
70 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
71 | selected_crop = crop_by_preview_name(image_path)
72 |
73 | im = Image.open(selected_crop)
74 | im = im.resize((1000,1000), Image.ANTIALIAS)
75 | im.save(selected_crop)
76 |
77 | crossed.draw(selected_crop, # input
78 | path, # output
79 | 3, # nibsize (line size in output svg)
80 | color, # line color
81 | 1.06, # scaling factor
82 | l1, l2, l3, l4, # levels
83 | 1, # type
84 | 820,975,0.3 # signature transform
85 | )
86 |
87 |
88 | def sketchy_large(image_path, path, color):
89 |
90 | im = Image.open(image_path)
91 | im = im.resize((1000,1000), Image.ANTIALIAS)
92 | im.save(image_path)
93 |
94 | sketchy.draw(image_path, # input
95 | path, # output
96 | 2, # nibsize (line size in output svg)
97 | 100, # max line length
98 | color, # line color
99 | 1.06, # scaling factor
100 | 1, # line size (internal line size for calculations)
101 | 820,975,0.3 # signature transform
102 | )
103 |
104 |
105 | def spiral_large(image_path, path, color):
106 |
107 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
108 | selected_crop = crop_by_preview_name(image_path)
109 |
110 | im = Image.open(selected_crop)
111 | im = im.resize((1000,1000), Image.ANTIALIAS)
112 | im.save(selected_crop)
113 |
114 | spiral.draw(selected_crop, # input
115 | path, # output
116 | 4, # nibsize (line size in output svg)
117 | color, # line color
118 | 1.06, # scaling factor
119 | l1, l2, l3, l4, # levels
120 | 3, # line spacing
121 | 820,975,0.3 # signature transform
122 | )
123 |
124 |
125 | def classic_extra_large(image_path, path, color):
126 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
127 | selected_crop = crop_by_preview_name(image_path)
128 |
129 | im = Image.open(selected_crop)
130 | im = im.resize((1000,1000), Image.ANTIALIAS)
131 | im.save(selected_crop)
132 |
133 | sig_scale = 1.0/1.39
134 |
135 | crossed.draw(selected_crop, # input
136 | path, # output
137 | 3, # nibsize (line size in output svg)
138 | color, # line color
139 | 1.39, # scaling factor
140 | l1, l2, l3, l4, # levels
141 | 2, # type
142 | 840, 975, 0.3 # signature transform
143 | )
144 |
145 |
146 | def spiral_extra_large(image_path, path, color):
147 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
148 | selected_crop = crop_by_preview_name(image_path)
149 |
150 | im = Image.open(selected_crop)
151 | im = im.resize((1000,1000), Image.ANTIALIAS)
152 | im.save(selected_crop)
153 |
154 | sig_scale = 1.0/1.39
155 |
156 | spiral.draw(selected_crop, # input
157 | path, # output
158 | 3, # nibsize (line size in output svg)
159 | color, # line color
160 | 1.39, # scaling factor
161 | l1, l2, l3, l4, # levels
162 | 2, # line spacing
163 | 840, 975, 0.3 # signature transform
164 | )
165 |
166 |
167 | def sketchy_extra_large(image_path, path, color):
168 |
169 | im = Image.open(image_path)
170 | im = im.resize((1390,1390), Image.ANTIALIAS)
171 | im.save(image_path)
172 |
173 | sig_scale = 1.0/1.39
174 |
175 | sketchy.draw(image_path, # input
176 | path, # output
177 | 2, # nibsize (line size in output svg)
178 | 100, # max line length
179 | color, # line color
180 | 1.00, # scaling factor
181 | 1, # line size (internal line size for calculations)
182 | 1225, 1370, 0.3 # signature transform
183 | )
184 |
185 | def classic_pen_a3_portrait(image_path, path, color):
186 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
187 | selected_crop = crop_by_preview_name(image_path)
188 |
189 | im = Image.open(selected_crop)
190 | im = im.resize((668,1000), Image.ANTIALIAS)
191 | im.save(selected_crop)
192 |
193 | crossed.draw(selected_crop, # input
194 | path, # output
195 | 2, # nibsize (line size in output svg)
196 | color, # line color
197 | 0.32, # scaling factor
198 | l1, l2, l3, l4, # levels
199 | 2, # type
200 | 500,975, 0.3 # signature transform
201 | )
202 |
203 | def classic_pen_a3_landscape(image_path, path, color):
204 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
205 | selected_crop = crop_by_preview_name(image_path)
206 |
207 | im = Image.open(selected_crop)
208 | im = im.resize((1000,572), Image.ANTIALIAS)
209 | im.save(selected_crop)
210 |
211 | crossed.draw(selected_crop, # input
212 | path, # output
213 | 2, # nibsize (line size in output svg)
214 | color, # line color
215 | 0.34, # scaling factor
216 | l1, l2, l3, l4, # levels
217 | 2, # type
218 | 830, 550, 0.3 # signature transform
219 | )
220 |
221 |
222 | def spiral_pen_a3_portrait(image_path, path, color):
223 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
224 | selected_crop = crop_by_preview_name(image_path)
225 |
226 | im = Image.open(selected_crop)
227 | im = im.resize((668,1000), Image.ANTIALIAS)
228 | im.save(selected_crop)
229 |
230 | spiral.draw(selected_crop, # input
231 | path, # output
232 | 2, # nibsize (line size in output svg)
233 | color, # line color
234 | 0.32, # scaling factor
235 | l1, l2, l3, l4, # levels
236 | 2, # line spacing
237 | 500,975, 0.3 # signature transform
238 | )
239 |
240 | def spiral_pen_a3_landscape(image_path, path, color):
241 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
242 | selected_crop = crop_by_preview_name(image_path)
243 |
244 | im = Image.open(selected_crop)
245 | im = im.resize((1000,572), Image.ANTIALIAS)
246 | im.save(selected_crop)
247 |
248 | spiral.draw(selected_crop, # input
249 | path, # output
250 | 2, # nibsize (line size in output svg)
251 | color, # line color
252 | 0.34, # scaling factor
253 | l1, l2, l3, l4, # levels
254 | 2, # line spacing
255 | 830, 550, 0.3 # signature transform
256 | )
257 |
258 |
259 | def sketchy_pen_a3_portrait(image_path, path, color):
260 |
261 | im = Image.open(image_path)
262 | im = im.resize((668,1000), Image.ANTIALIAS)
263 | im.save(image_path)
264 |
265 | sketchy.draw(image_path, # input
266 | path, # outputsketchy_pen_a3
267 | 2, # nibsize (line size in output svg)
268 | 100, # max line length
269 | color, # line color
270 | 0.32, # scaling factor
271 | 1, # line size (internal line size for calculations)
272 | 500,975, 0.3 # signature transform
273 | )
274 |
275 | def sketchy_pen_a3_landscape(image_path, path, color):
276 |
277 | im = Image.open(image_path)
278 | im = im.resize((1000,572), Image.ANTIALIAS)
279 | im.save(image_path)
280 |
281 | sketchy.draw(image_path, # input
282 | path, # outputsketchy_pen_a3
283 | 2, # nibsize (line size in output svg)
284 | 100, # max line length
285 | color, # line color
286 | 0.34, # scaling factor
287 | 1, # line size (internal line size for calculations)
288 | 830, 550, 0.3 # signature transform
289 | )
290 |
291 | def classic_pen_a3(image_path, path, color):
292 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
293 | selected_crop = crop_by_preview_name(image_path)
294 |
295 | im = Image.open(selected_crop)
296 | im = im.resize((1000,1000), Image.ANTIALIAS)
297 | im.save(selected_crop)
298 |
299 | crossed.draw(selected_crop, # input
300 | path, # output
301 | 3, # nibsize (line size in output svg)
302 | color, # line color
303 | 0.21, # scaling factor
304 | l1, l2, l3, l4, # levels
305 | 1, # type
306 | 730,970,0.5 # signature transform
307 | )
308 |
309 |
310 | def spiral_pen_a3(image_path, path, color):
311 | l1, l2, l3, l4 = levels_by_preview_name(image_path)
312 | selected_crop = crop_by_preview_name(image_path)
313 |
314 | im = Image.open(selected_crop)
315 | im = im.resize((1000,1000), Image.ANTIALIAS)
316 | im.save(selected_crop)
317 |
318 | spiral.draw(selected_crop, # input
319 | path, # output
320 | 3, # nibsize (line size in output svg)
321 | color, # line color
322 | 0.21, # scaling factor
323 | l1, l2, l3, l4, # levels
324 | 2, # line spacing
325 | 730,970,0.5 # signature transform
326 | )
327 |
328 |
329 | def sketchy_pen_a3(image_path, path, color):
330 |
331 | im = Image.open(image_path)
332 | im = im.resize((1000,1000), Image.ANTIALIAS)
333 | im.save(image_path)
334 |
335 | sketchy.draw(image_path, # input
336 | path, # output
337 | 3, # nibsize (line size in output svg)
338 | 100, # max line length
339 | color, # line color
340 | 0.21, # scaling factor
341 | 1, # line size (internal line size for calculations)
342 | 730, 970, 0.5 # signature transform
343 | )
344 |
345 |
346 | sketchy_pen_a3("image.png", "image1.svg", "#ff0000")
347 | spiral_pen_a3("image.png", "image2.svg", "#ff0000")
348 | classic_pen_a3("image.png", "image3.svg", "#ff0000")
349 |
350 | sketchy_pen_a3_landscape("image.png", "image4.svg", "#ff0000")
351 | spiral_pen_a3_landscape("image.png", "image5.svg", "#ff0000")
352 | classic_pen_a3_landscape("image.png", "image6.svg", "#ff0000")
353 |
354 | sketchy_pen_a3_portrait("image.png", "image7.svg", "#ff0000")
355 | spiral_pen_a3_portrait("image.png", "image8.svg", "#ff0000")
356 | classic_pen_a3_portrait("image.png", "image9.svg", "#ff0000")
357 |
358 | sketchy_extra_large("image.png", "image10.svg", "#ff00ff")
359 | spiral_extra_large("image.png", "image11.svg", "#ff00ff")
360 | classic_extra_large("image.png", "image12.svg", "#ff00ff")
361 |
362 | sketchy_large("image.png", "image13.svg", "#ff0000")
363 | spiral_large("image.png", "image14.svg", "#ff0000")
364 | classic_large("image.png", "image15.svg", "#ff0000")
365 |
366 | sketchy_small("image.png", "image16.svg", "#ffff00")
367 | spiral_small("image.png", "image17.svg", "#ffff00")
368 | classic_small("image.png", "image18.svg", "#ffff00")
369 |
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/test/image.png:
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https://raw.githubusercontent.com/fullscreennl/blackstripes-python-extensions/366d3899b79daad5b6c5332a0ec63201374e46e4/test/image.png
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/test/luxx_test.py:
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1 | from blackstripes import spiral
2 | from blackstripes import crossed
3 |
4 | crossed.draw("image.png", # input
5 | "image_crossed.svg", # output
6 | 2.0, # nibsize (line size in output svg)
7 | "#2200aa", # line color
8 | 0.32, # scaling factor
9 | 200, 0, 110, 0, # levels ** just null two invisible layers **
10 | 2, # type
11 | 540,1021,0.0 # signature transform
12 | )
13 |
14 | spiral.draw("image.png", # input
15 | "image_spiral.svg", # output
16 | 2.0 , # nibsize (line size in output svg)
17 | "#aa0000", # line color
18 | 0.32, # scaling factor
19 | 180, 108, 180, 108, # levels
20 | 2, # linespacing
21 | 540,1021,0.0 # signature transform
22 | )
23 |
24 | spiral.draw("image.png", # input
25 | "image_spiral_round.svg", # output
26 | 2.0 , # nibsize (line size in output svg)
27 | "#aa0000", # line color
28 | 0.32, # scaling factor
29 | 180, 108, 180, 108, # levels
30 | 2, # linespacing
31 | 540,1021,0.0, # signature transform
32 | 1 # round shaped drawing if True
33 | )
34 |
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/test/sketchy-test.py:
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1 | from blackstripes import sketchy
2 |
3 | sketchy.draw("ali.png", # input
4 | "ali_sketchy.svg", # output
5 | 1, # nibsize (line size in output svg)
6 | 100, # max line length
7 | "#000000", # line color
8 | 0.32, # scaling factor
9 | 1, # line size (internal line size for calculations)
10 | 540, 1021, 0.7 # signature transform tx, ty, scale
11 | )
12 |
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/test/spiral-test.py:
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1 | from blackstripes import spiral
2 |
3 | spiral.draw("ali.png", # input
4 | "ali_spiral.svg", # output
5 | 2.0 , # nibsize (line size in output svg)
6 | "#aa0000", # line color
7 | 0.32, # scaling factor
8 | 180, 108, 180, 108, # levels
9 | 2, # linespacing
10 | 540,1021,0.7 # signature transform
11 | )
12 |
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