├── README.md
└── main.cpp


/README.md:
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1 | # hand-gesture-recognition-opencv
2 | 
3 | Using OpenCV C++ API this program recognizes hand gestures and give different outputs according to hand gesture. 
4 | 


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/main.cpp:
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  1 | #include "opencv2/imgproc/imgproc.hpp"
  2 | #include <opencv2/highgui/highgui.hpp>
  3 | #include <iostream>
  4 | 
  5 | using namespace cv;
  6 | using namespace std;
  7 | 
  8 | int main( int argc, const char** argv)
  9 | {
 10 | 
 11 | 
 12 |     VideoCapture cam(0);
 13 |     if(!cam.isOpened()){
 14 |         cout<<"ERROR not opened "<< endl;
 15 |         return -1;
 16 |     }
 17 |     Mat img;
 18 |     Mat img_threshold;
 19 |     Mat img_gray;
 20 |     Mat img_roi;
 21 |     namedWindow("Original_image",CV_WINDOW_AUTOSIZE);
 22 |     namedWindow("Gray_image",CV_WINDOW_AUTOSIZE);
 23 |     namedWindow("Thresholded_image",CV_WINDOW_AUTOSIZE);
 24 |     namedWindow("ROI",CV_WINDOW_AUTOSIZE);
 25 |     char a[40];
 26 |     int count =0;
 27 |     while(1){
 28 |         bool b=cam.read(img);
 29 |         if(!b){
 30 |             cout<<"ERROR : cannot read"<<endl;
 31 |             return -1;
 32 |         }
 33 |         Rect roi(340,100,270,270);
 34 |         img_roi=img(roi);
 35 |         cvtColor(img_roi,img_gray,CV_RGB2GRAY);
 36 | 
 37 |         GaussianBlur(img_gray,img_gray,Size(19,19),0.0,0);
 38 |         threshold(img_gray,img_threshold,0,255,THRESH_BINARY_INV+THRESH_OTSU);
 39 | 
 40 |         vector<vector<Point> >contours;
 41 |         vector<Vec4i>hierarchy;
 42 |         findContours(img_threshold,contours,hierarchy,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE,Point());
 43 |         if(contours.size()>0){
 44 |                 size_t indexOfBiggestContour = -1;
 45 | 	            size_t sizeOfBiggestContour = 0;
 46 | 
 47 | 	            for (size_t i = 0; i < contours.size(); i++){
 48 | 		           if(contours[i].size() > sizeOfBiggestContour){
 49 | 			       sizeOfBiggestContour = contours[i].size();
 50 | 			       indexOfBiggestContour = i;
 51 | 		          }
 52 |                 }
 53 |                 vector<vector<int> >hull(contours.size());
 54 |                 vector<vector<Point> >hullPoint(contours.size());
 55 |                 vector<vector<Vec4i> >defects(contours.size());
 56 |                 vector<vector<Point> >defectPoint(contours.size());
 57 |                 vector<vector<Point> >contours_poly(contours.size());
 58 |                 Point2f rect_point[4];
 59 |                 vector<RotatedRect>minRect(contours.size());
 60 |                 vector<Rect> boundRect(contours.size());
 61 |                 for(size_t i=0;i<contours.size();i++){
 62 |                     if(contourArea(contours[i])>5000){
 63 |                         convexHull(contours[i],hull[i],true);
 64 |                         convexityDefects(contours[i],hull[i],defects[i]);
 65 |                         if(indexOfBiggestContour==i){
 66 |                             minRect[i]=minAreaRect(contours[i]);
 67 |                             for(size_t k=0;k<hull[i].size();k++){
 68 |                                 int ind=hull[i][k];
 69 |                                 hullPoint[i].push_back(contours[i][ind]);
 70 |                             }
 71 |                             count =0;
 72 | 
 73 |                             for(size_t k=0;k<defects[i].size();k++){
 74 |                                 if(defects[i][k][3]>13*256){
 75 |                                  /*   int p_start=defects[i][k][0];   */
 76 |                                     int p_end=defects[i][k][1];
 77 |                                     int p_far=defects[i][k][2];
 78 |                                     defectPoint[i].push_back(contours[i][p_far]);
 79 |                                     circle(img_roi,contours[i][p_end],3,Scalar(0,255,0),2);
 80 |                                     count++;
 81 |                                 }
 82 | 
 83 |                             }
 84 | 
 85 |                             if(count==1)
 86 |                                 strcpy(a,"Hello :D ");
 87 |                             else if(count==2)
 88 |                                 strcpy(a,"Peace :) ");
 89 |                             else if(count==3)
 90 |                                 strcpy(a,"3 it is !!");
 91 |                             else if(count==4)
 92 |                                 strcpy(a,"0100");
 93 |                             else if(count==5)
 94 |                                 strcpy(a,"FIVE");
 95 |                             else
 96 |                                 strcpy(a,"Welcome !!");
 97 | 
 98 |                             putText(img,a,Point(70,70),CV_FONT_HERSHEY_SIMPLEX,3,Scalar(255,0,0),2,8,false);
 99 |                             drawContours(img_threshold, contours, i,Scalar(255,255,0),2, 8, vector<Vec4i>(), 0, Point() );
100 |                             drawContours(img_threshold, hullPoint, i, Scalar(255,255,0),1, 8, vector<Vec4i>(),0, Point());
101 |                             drawContours(img_roi, hullPoint, i, Scalar(0,0,255),2, 8, vector<Vec4i>(),0, Point() );
102 |                             approxPolyDP(contours[i],contours_poly[i],3,false);
103 |                             boundRect[i]=boundingRect(contours_poly[i]);
104 |                             rectangle(img_roi,boundRect[i].tl(),boundRect[i].br(),Scalar(255,0,0),2,8,0);
105 |                             minRect[i].points(rect_point);
106 |                             for(size_t k=0;k<4;k++){
107 |                                 line(img_roi,rect_point[k],rect_point[(k+1)%4],Scalar(0,255,0),2,8);
108 |                             }
109 | 
110 |                         }
111 |                     }
112 | 
113 |                 }
114 |             imshow("Original_image",img);
115 |             imshow("Gray_image",img_gray);
116 |             imshow("Thresholded_image",img_threshold);
117 |             imshow("ROI",img_roi);
118 |             if(waitKey(30)==27){
119 |                   return -1;
120 |              }
121 | 
122 |         }
123 | 
124 |     }
125 | 
126 |      return 0;
127 | }
128 | 
129 | 
130 | 


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