first commit

README.md

@@ -0,0 +1 @@
+http://blog.ayoungprogrammer.com/2013/03/tutorial-creating-multiple-choice.html

main.cpp

@@ -1,88 +1,219 @@
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/imgproc/imgproc.hpp>
-#include <zbar.h>
 #include <iostream>
+#include <vector>
+#include <algorithm>
+
+//g++ main.cpp -o main -I /usr/local/include/opencv -lopencv_core -lopencv_imgproc -lopencv_highgui
 
 using namespace cv;
 using namespace std;
-using namespace zbar;
 
-//g++ main.cpp /usr/local/include/ /usr/local/lib/ -lopencv_highgui.2.4.8 -lopencv_core.2.4.8
 
-int main(int argc, char* argv[])
+cv::Point2f computeIntersect(cv::Vec4i a, cv::Vec4i b)
 {
-    VideoCapture cap(0); // open the video camera no. 0
-
-   // cap.set(CV_CAP_PROP_FRAME_WIDTH,800);
-   // cap.set(CV_CAP_PROP_FRAME_HEIGHT,640);
+    int x1 = a[0], y1 = a[1], x2 = a[2], y2 = a[3];
+    int x3 = b[0], y3 = b[1], x4 = b[2], y4 = b[3];
 
-    if (!cap.isOpened())  // if not success, exit program
+    if (float d = ((float)(x1-x2) * (y3-y4)) - ((y1-y2) * (x3-x4)))
     {
-        cout << "Cannot open the video cam" << endl;
-        return -1;
+        cv::Point2f pt;
+        pt.x = ((x1*y2 - y1*x2) * (x3-x4) - (x1-x2) * (x3*y4 - y3*x4)) / d;
+        pt.y = ((x1*y2 - y1*x2) * (y3-y4) - (y1-y2) * (x3*y4 - y3*x4)) / d;
+        return pt;
     }
-
-
-    ImageScanner scanner;  
-      scanner.set_config(ZBAR_NONE, ZBAR_CFG_ENABLE, 1);  
-
-   double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get the width of frames of the video
-   double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get the height of frames of the video
-
-    cout << "Frame size : " << dWidth << " x " << dHeight << endl;
-
-    namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"
-
-    while (1)
-    {
-        Mat frame;
-
-        bool bSuccess = cap.read(frame); // read a new frame from video
-
-         if (!bSuccess) //if not success, break loop
-        {
-             cout << "Cannot read a frame from video stream" << endl;
-             break;
+    else
+        return cv::Point2f(-1, -1);
+}
+
+bool comparator2(double a,double b){  
+  return a<b;  
+ }  
+ bool comparator3(Vec3f a,Vec3f b){  
+  return a[0]<b[0];  
+ }  
+
+bool comparator(Point2f a,Point2f b){  
+  return a.x<b.x;  
+  }  
+ void sortCorners(std::vector<cv::Point2f>& corners, cv::Point2f center)  
+ {  
+
+
+   std::vector<cv::Point2f> top, bot;  
+   for (int i = 0; i < corners.size(); i++)  
+   {  
+     if (corners[i].y < center.y)  
+       top.push_back(corners[i]);  
+     else  
+       bot.push_back(corners[i]);  
+   }  
+
+
+  sort(top.begin(),top.end(),comparator);  
+  sort(bot.begin(),bot.end(),comparator); 
+
+   cv::Point2f tl = top[0];  
+   cv::Point2f tr = top[top.size()-1];  
+   cv::Point2f bl = bot[0];  
+   cv::Point2f br = bot[bot.size()-1]; 
+   corners.clear();  
+   corners.push_back(tl);  
+   corners.push_back(tr);  
+   corners.push_back(br);  
+   corners.push_back(bl);  
+ }  
+
+
+int main(int argc, char* argv[]){
+
+  Mat img = imread("example.jpg",0);
+
+  cv::Size size(3,3);  
+  cv::GaussianBlur(img,img,size,0);  
+  adaptiveThreshold(img, img,255,CV_ADAPTIVE_THRESH_MEAN_C, CV_THRESH_BINARY,75,10);  
+  cv::bitwise_not(img, img);    
+
+  cv::Mat img2;  
+  cvtColor(img,img2, CV_GRAY2RGB);  
+
+  cv::Mat img3;  
+  cvtColor(img,img3, CV_GRAY2RGB); 
+
+  vector<Vec4i> lines;  
+  HoughLinesP(img, lines, 1, CV_PI/180, 80, 400, 10);  
+  for( size_t i = 0; i < lines.size(); i++ )  
+  {  
+   Vec4i l = lines[i];  
+   line( img2, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 3, CV_AA);   
+  }  
+
+  imshow("example",img2);
+
+  std::vector<cv::Point2f> corners;
+  for (int i = 0; i < lines.size(); i++)
+  {
+      for (int j = i+1; j < lines.size(); j++)
+      {
+          cv::Point2f pt = computeIntersect(lines[i], lines[j]);
+          if (pt.x >= 0 && pt.y >= 0 && pt.x < img.cols && pt.y < img.rows)
+              corners.push_back(pt);
+      }
+  }
+
+   // Get mass center  
+  cv::Point2f center(0,0);  
+  for (int i = 0; i < corners.size(); i++)  
+  center += corners[i];  
+  center *= (1. / corners.size()); 
+
+  sortCorners(corners, center); 
+
+  Rect r = boundingRect(corners); 
+  cout<<r<<endl;
+  cv::Mat quad = cv::Mat::zeros(r.height, r.width, CV_8UC3);  
+  // Corners of the destination image  
+  std::vector<cv::Point2f> quad_pts;  
+  quad_pts.push_back(cv::Point2f(0, 0));  
+  quad_pts.push_back(cv::Point2f(quad.cols, 0));  
+  quad_pts.push_back(cv::Point2f(quad.cols, quad.rows));  
+  quad_pts.push_back(cv::Point2f(0, quad.rows));  
+
+  // Get transformation matrix  
+  cv::Mat transmtx = cv::getPerspectiveTransform(corners, quad_pts);  
+  // Apply perspective transformation  
+  cv::warpPerspective(img3, quad, transmtx, quad.size());  
+
+  imshow("example2",quad);
+
+  Mat cimg;
+
+  cvtColor(quad,cimg, CV_BGR2GRAY);
+  vector<Vec3f> circles;  
+  HoughCircles(cimg, circles, CV_HOUGH_GRADIENT, 1, img.rows/8, 100, 75, 0, 0 );  
+  for( size_t i = 0; i < circles.size(); i++ ){  
+    Point center(cvRound(circles[i][0]), cvRound(circles[i][1]));
+    // circle center  
+    circle( quad, center, 3, Scalar(0,255,0), -1, 8, 0 );
+  }
+
+  imshow("example4",quad);
+  waitKey();
+
+  double averR = 0;
+  vector<double> row;
+  vector<double> col;
+
+  //Find rows and columns of circles for interpolation
+  for(int i=0;i<circles.size();i++){  
+    bool found = false;  
+    int r = cvRound(circles[i][2]);
+    averR += r;
+    int x = cvRound(circles[i][0]);  
+    int y = cvRound(circles[i][1]);
+    for(int j=0;j<row.size();j++){
+      double y2 = row[j];
+      if(y - r < y2 && y + r > y2){
+        found = true;
+        break;
+      }
+    }
+    if(!found){
+      row.push_back(y);
+    }
+    found = false;
+    for(int j=0;j<col.size();j++){
+      double x2 = col[j];
+      if(x - r < x2 && x + r > x2){
+        found = true;
+        break;
+      }
+    }
+    if(!found){  
+      col.push_back(x);
+    }
+  }
+
+  averR /= circles.size();
+
+  sort(row.begin(),row.end(),comparator2);
+  sort(col.begin(),col.end(),comparator2);
+
+  for(int i=0;i<row.size();i++){
+    double max = 0;  
+    double y = row[i];
+    int ind = -1;
+    for(int j=0;j<col.size();j++){
+      double x = col[j];
+      Point c(x,y);  
+
+      //Use an actual circle if it exists
+      for(int k=0;k<circles.size();k++){
+        double x2 = circles[k][0];
+        double y2 = circles[k][1];
+        if(abs(y2-y)<averR && abs(x2-x)<averR){
+          x = x2;
+          y = y2;
         }
-
-        Mat grey;
-        cvtColor(frame,grey,CV_BGR2GRAY);
-
-        int width = frame.cols;  
-        int height = frame.rows;  
-        uchar *raw = (uchar *)grey.data;  
-        // wrap image data  
-        Image image(width, height, "Y800", raw, width * height);  
-        // scan the image for barcodes  
-        int n = scanner.scan(image);  
-        // extract results  
-        for(Image::SymbolIterator symbol = image.symbol_begin();  
-        symbol != image.symbol_end();  
-        ++symbol) {  
-                vector<Point> vp;  
-        // do something useful with results  
-        cout << "decoded " << symbol->get_type_name()  << " symbol \"" << symbol->get_data() << '"' <<" "<< endl;  
-           int n = symbol->get_location_size();  
-           for(int i=0;i<n;i++){  
-                vp.push_back(Point(symbol->get_location_x(i),symbol->get_location_y(i))); 
-           }  
-           RotatedRect r = minAreaRect(vp);  
-           Point2f pts[4];  
-           r.points(pts);  
-           for(int i=0;i<4;i++){  
-                line(frame,pts[i],pts[(i+1)%4],Scalar(255,0,0),3);  
-           }  
-           //cout<<"Angle: "<<r.angle<<endl;  
-        }  
-
-        imshow("MyVideo", frame); //show the frame in "MyVideo" window
-
-        if (waitKey(30) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
-       {
-            cout << "esc key is pressed by user" << endl;
-            break; 
-       }
+      }
+
+      // circle outline  
+      circle( quad, c, averR, Scalar(0,0,255), 3, 8, 0 );  
+      Rect rect(x-averR,y-averR,2*averR,2*averR);  
+      Mat submat = cimg(rect);  
+      double p =(double)countNonZero(submat)/(submat.size().width*submat.size().height);  
+      if(p>=0.3 && p>max){  
+        max = p;  
+        ind = j;  
+      }  
     }
-    return 0;
-
+    if(ind==-1)printf("%d:-",i+1);  
+    else printf("%d:%c",i+1,'A'+ind);  
+    cout<<endl;  
+  }  
+
+  // circle outline*/  
+  imshow("example3",quad);
+  waitKey();
+  return 0;
 }