├── 5.png
├── README.md
├── demo.cpp
├── twoPass.cpp
└── twoPass.h


/5.png:
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https://raw.githubusercontent.com/polyGithub/opencv_twoPass/13feff495705ce3f4031424bb497cdcacea1c3a6/5.png


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/README.md:
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 1 | # opencv_twoPass
 2 | 图像目标检测识别，计算物体个数，针对电子元器件计算.主要是利用连通区域发现算法，发现所有连通区域，获取最小部分的连通区域集合（图片预处理很关键），根据此连通区域面积， 作为单个器件大小，从而求取出粘连部分的个数，完成对整个元器件的计算，准备率相当的高，目测可达99%以上
 3 | 
 4 | 
 5 | 
 6 | 代码编译
 7 | 
 8 | g++ demo.cpp twoPass.cpp -o test `pkg-config --cflags --libs opencv`
 9 | 
10 | 运行
11 | 
12 | ./test 5.png
13 | 


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/demo.cpp:
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  1 | #include <opencv2/opencv.hpp>
  2 | #include <iostream>
  3 | #include <stdio.h>
  4 | #include <string>
  5 | #include <sstream>
  6 | #include "twoPass.h"
  7 | #include <opencv2/highgui/highgui.hpp>
  8 | using namespace std;
  9 | using namespace cv;
 10 | 
 11 | cv::Scalar getRandomColor()
 12 | {
 13 | 	uchar r = 255 * (rand() / (1.0 + RAND_MAX));
 14 | 	uchar g = 255 * (rand() / (1.0 + RAND_MAX));
 15 | 	uchar b = 255 * (rand() / (1.0 + RAND_MAX));
 16 | 	return cv::Scalar(b, g, r);
 17 | }
 18 | 
 19 | cv::Mat showColorLabel(cv::Mat label)
 20 | {
 21 | 	int imgW = label.cols;
 22 | 	int imgH = label.rows;
 23 | 	std::map<int, cv::Scalar> colors;
 24 | 
 25 | 	cv::Mat colorLabel = cv::Mat::zeros(imgH, imgW, CV_8UC3);
 26 | 	int *pLabel = (int*)label.data;
 27 | 	uchar *pColorLabel = colorLabel.data;
 28 | 	for (int i = 0; i < imgH; i++)
 29 | 	{
 30 | 		//printf("\n");
 31 | 		for (int j = 0; j < imgW; j++)
 32 | 		{
 33 | 			int idx = (i*imgW + j) * 3;
 34 | 			int pixelValue = pLabel[i*imgW + j];
 35 | 			//printf(" %02x",pixelValue);
 36 | 			if (pixelValue > 0)
 37 | 			{
 38 | 				if (colors.count(pixelValue) <= 0)
 39 | 				{
 40 | 					colors[pixelValue] = getRandomColor();		
 41 | 				}
 42 | 					cv::Scalar color = colors[pixelValue];
 43 | 					pColorLabel[idx + 0] = color[0];
 44 | 					pColorLabel[idx + 1] = color[1];
 45 | 					pColorLabel[idx + 2] = color[2];
 46 | 			}
 47 | 		}
 48 | 	}
 49 | 
 50 | 	return colorLabel;
 51 | }
 52 | 
 53 | int main(int argc, char *argv[])
 54 | {
 55 | 	string imageName = argv[1];
 56 | 	cv::Mat srcImage  = cv::imread(imageName, 1);
 57 | 	if (!srcImage.data )
 58 | 	{
 59 | 		cout << "No image data" << endl;
 60 | 		return 0;
 61 | 	}
 62 | 	cv::Mat image;
 63 | 	cv::cvtColor(srcImage, image, CV_RGB2GRAY);
 64 | 
 65 | 	cv::Mat threshImg;
 66 | 	cv::threshold(image, threshImg, 140, 255, cv::THRESH_BINARY);
 67 | 	cv::bitwise_not(threshImg, threshImg);
 68 | 
 69 | 	cv::imshow("threshImg", threshImg);
 70 | 
 71 | 	Mat element = getStructuringElement(MORPH_RECT,Size(3,3));
 72 |   Mat destImage;
 73 |   erode(threshImg,destImage,element);
 74 | 	cv::imshow("destImage", destImage);
 75 | 
 76 | 	element = getStructuringElement(MORPH_RECT,Size(5,5));
 77 |   dilate( destImage, destImage, element );
 78 | 
 79 | 	cv::Mat labelImg=cv::Mat::zeros(image.size(), CV_32SC1);
 80 | 	int maxLabel = -1;
 81 | 	TwoPass twoPassMethod(destImage.cols*destImage.rows);
 82 | 	twoPassMethod.run(destImage, labelImg, maxLabel);
 83 | 
 84 | 	cv::imshow("labelImg", labelImg * 60);
 85 | 	cv::Mat colorLabelImg = showColorLabel(labelImg);
 86 | 
 87 | 	cv::imshow("colorLabel", colorLabelImg);
 88 | 
 89 | 	vector< vector<cv::Point> > contours;
 90 | 
 91 | 	findContours(destImage,contours,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE);
 92 | 	drawContours(destImage,contours,-1,cv::Scalar(128),1); 
 93 | 	imshow("dilate",destImage);
 94 | 	
 95 | 	cout<<contours.size()<<endl;
 96 | 	double min_area = 10000.0;
 97 | 	double area = 0.0;
 98 | 	for( size_t i = 0; i< contours.size(); i++ ) // iterate through each contour.    
 99 | 	{        
100 | 		area = contourArea( contours[i] );  //  Find the area of contour    
101 | 		//cout<<"area: " << area<<endl;     
102 | 		if( area < min_area ){min_area = area;}    
103 | 	}   
104 | 	//printf("min:%f\n",min_area);
105 | 	char ss[10] = {0};
106 | 	char * snum = ss;
107 | 	int n = 0;
108 | 	for( size_t i = 0; i< contours.size(); i++ ) // iterate through each contour.    
109 | 	{        
110 | 		area = contourArea( contours[i] );  //  Find the area of contour 
111 | 		int k = (int)(area/min_area);
112 | 		n = n + k;       
113 | 		if( k > 1 )       
114 | 		{            
115 | 			Rect r0=boundingRect(contours[i]);
116 | 			rectangle(srcImage,r0,cv::Scalar(0, 0, 255),1);
117 | 			sprintf(snum,"%d",k);
118 | 			putText(srcImage, snum, Point(r0.x, r0.y), FONT_HERSHEY_SIMPLEX, 1, Scalar(0,0,255), 1, 1);                 
119 | 		}    
120 | 	} 
121 | 	char str[10] = {0};
122 | 	char * num = str;
123 | 	sprintf(num,"%d",n);
124 | 	putText(srcImage, num, Point(50, 50), FONT_HERSHEY_SIMPLEX, 1, Scalar(0,255,0), 2, 2);
125 | 	cv::imshow("result", srcImage);
126 | 	cv::waitKey(0);
127 | }
128 | 


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/twoPass.cpp:
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  1 | #include "twoPass.h"
  2 | 
  3 | TwoPass::TwoPass(int size)
  4 | {
  5 | 	int maxSize = size;
  6 | 	parent = (int*)malloc(maxSize * sizeof(int));
  7 | 	memset(parent, 0, maxSize);
  8 | }
  9 | 
 10 | TwoPass::~TwoPass()
 11 | {
 12 | 	free(parent);
 13 | }
 14 | 
 15 | // find the root of label x
 16 | int TwoPass::Find(int x, int parent[])
 17 | {
 18 | 	//assert(x < maxSize);
 19 | 	int i = x;
 20 | 	while (0 != parent[i])
 21 | 		i = parent[i];
 22 |   //cout << "i " << i <<endl;
 23 | 	return i;
 24 | }
 25 | 
 26 | // set label x and label y to the same connected-region
 27 | void TwoPass::Union(int x, int y, int parent[])
 28 | {
 29 | 	//assert(x < maxSize && y < maxSize);
 30 | 	int i = x;
 31 | 	int j = y;
 32 | 	while (0 != parent[i])
 33 | 		i = parent[i];
 34 | 	while (0 != parent[j])
 35 | 		j = parent[j];
 36 | 	if (i != j)
 37 | 		parent[i] = j;
 38 | }
 39 | 
 40 | void TwoPass::twoPassConnectComponent(cv::Mat binaryImg, cv::Mat &dst)
 41 | {
 42 | 	int imgW = binaryImg.cols;
 43 | 	int imgH = binaryImg.rows;
 44 | 	int channel = binaryImg.channels();
 45 | 	int type = binaryImg.type();
 46 | 	// first pass
 47 | 	int label = 1;
 48 | 
 49 | 	//init lable image
 50 | 	for (int y = 0; y < imgH; y++)
 51 | 	{
 52 | 		for (int x = 0; x < imgW; x++)
 53 | 		{
 54 | 			if (binaryImg.at<uchar>(y, x) != 0)
 55 | 			{
 56 | 				//left and up labels
 57 | 				int left = (x - 1 < 0) ? 0 : dst.at<int>(y, x - 1);
 58 | 				int up   = (y - 1 < 0) ? 0 : dst.at<int>(y - 1, x);
 59 | 				//at least one label is marked
 60 | 				if (left != 0 || up != 0)
 61 | 				{
 62 | 					//two labels are marked
 63 | 					if (left != 0 && up != 0)
 64 | 					{
 65 | 						//adopt smaller label
 66 | 						dst.at<int>(y, x) = min(left, up);
 67 | 						if (left <= up)
 68 | 							Union(up, left, parent);
 69 | 						else if (up<left)
 70 | 							Union(left, up, parent);
 71 | 					}
 72 | 					else
 73 | 					{
 74 | 						//adopt larger label
 75 | 						dst.at<int>(y, x) = max(left, up);
 76 | 					}
 77 | 				}
 78 | 				else
 79 | 				{
 80 | 					//non of two labels is markded, so add a new label
 81 | 					dst.at<int>(y, x) = ++label;
 82 | 				}
 83 | 			}
 84 | 		}
 85 | 	}
 86 |  
 87 | 	//second pass 
 88 | 	for (int y = 0; y < imgH; y++)
 89 | 	{
 90 | //printf("\n");
 91 | 		for (int x = 0; x < imgW; x++)
 92 | 		{
 93 | 			if (binaryImg.at<uchar>(y, x) != 0)
 94 | 				dst.at<int>(y, x) = Find(dst.at<int>(y, x), parent);
 95 | //				printf("%d ",dst.at<int>(y, x));
 96 | 		}
 97 | 	}
 98 | }
 99 | 
100 | //find the max label value
101 | void TwoPass::findMaxLabel(cv::Mat labelImg, int &max)
102 | {
103 | 	int imgH = labelImg.rows;
104 | 	int imgW = labelImg.cols;
105 | 	int *pLabel = (int*)labelImg.data;
106 | 
107 | 	for (int i = 0; i < imgH; i++)
108 | 	{
109 | 		for (int j = 0; j < imgW; j++)
110 | 		{
111 | 			int idx = i*imgW + j;
112 | 			if (pLabel[idx] > max) max = pLabel[idx];
113 | 		}
114 | 	}
115 | }
116 | 
117 | void TwoPass::run(const cv::Mat threshImg, cv::Mat &labelImg, int &max)
118 | {
119 | 	//detect connected-region using two Pass method
120 | 	twoPassConnectComponent(threshImg, labelImg);
121 | 
122 | 	//find the largest label
123 | 	findMaxLabel(labelImg, max);
124 | 	//printf("max=%d\n",max);
125 | 
126 | 
127 |   cout << "max " << max <<endl;
128 | }
129 | 


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/twoPass.h:
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 1 | #pragma once
 2 | #include <iostream>
 3 | #include <string>
 4 | #include <opencv2/opencv.hpp>
 5 | #include <map>
 6 | #include <stdio.h>
 7 | using namespace std;
 8 | 
 9 | class TwoPass
10 | {
11 | public:
12 | 	TwoPass(int size);
13 | 	~TwoPass();
14 | 
15 | private:
16 | 	int maxSize;
17 | 	int *parent;
18 | 
19 | private:
20 | 	int Find(int x, int parent[]);
21 | 	void Union(int x, int y, int parent[]);
22 | 	void twoPassConnectComponent(cv::Mat binaryImg, cv::Mat &dstImg);
23 | 	void findMaxLabel(cv::Mat labelImg, int & max);
24 | 
25 | public:
26 | 	void run(const cv::Mat img, cv::Mat &labelImg, int &max);
27 | 
28 | };
29 | 


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