OpenCV计算连通区域数目与最大连通区域并标示出

 #include <stdio.h>
 #include <cv.h>
 #include <highgui.h>

 #pragma comment(lib, "cv.lib")
 #pragma comment(lib, "cxcore.lib")
 #pragma comment(lib, "highgui.lib")

 int main( int argc, char** argv )
 {
     IplImage* src = cvLoadImage(".\\wind.png", CV_LOAD_IMAGE_GRAYSCALE);
     IplImage* dst = cvCreateImage(cvGetSize(src), 8, 3);
     CvMemStorage* storage = cvCreateMemStorage(0);
     CvSeq* contour = 0;
     cvThreshold(src, src,120, 255, CV_THRESH_BINARY);   // 二值化
     cvNamedWindow("Source", 1);
     cvShowImage("Source", src);
     // 提取轮廓
     int contour_num = cvFindContours(src, storage, &contour, sizeof(CvContour), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);
     cvZero(dst);        // 清空数组
     CvSeq *_contour = contour;
     double maxarea = 0;
     double minarea = 100;
     int m = 0;
     for( ; contour != 0; contour = contour->h_next )
     {

         double tmparea = fabs(cvContourArea(contour));
         if(tmparea < minarea)
         {
             cvSeqRemove(contour, 0); // 删除面积小于设定值的轮廓
             continue;
         }
         CvRect aRect = cvBoundingRect( contour, 0 );
         if ((aRect.width/aRect.height)<1)
         {
             cvSeqRemove(contour, 0); //删除宽高比例小于设定值的轮廓
             continue;
         }
         if(tmparea > maxarea)
         {
             maxarea = tmparea;
         }
         m++;
         // 创建一个色彩值
         CvScalar color = CV_RGB( 0, 255, 255 );

         //max_level 绘制轮廓的最大等级。如果等级为0，绘制单独的轮廓。如果为1，绘制轮廓及在其后的相同的级别下轮廓
         //如果值为2，所有的轮廓。如果等级为2，绘制所有同级轮廓及所有低一级轮廓，诸此种种
         //如果值为负数，函数不绘制同级轮廓，但会升序绘制直到级别为abs(max_level)-1的子轮廓
         cvDrawContours(dst, contour, color, color, -1, 1, 8);   //绘制外部和内部的轮廓
     }
     contour = _contour;
     int count = 0;
     for(; contour != 0; contour = contour->h_next)
     {
         count++;
         double tmparea = fabs(cvContourArea(contour));
         if (tmparea == maxarea)
         {
             CvScalar color = CV_RGB( 255, 0, 0);
             cvDrawContours(dst, contour, color, color, -1, 1, 8);
         }
     }
     printf("The total number of contours is:%d", count);
     cvNamedWindow("Components", 1);
     cvShowImage("Components", dst);
     cvWaitKey(0);
     cvDestroyWindow("Source");
     cvReleaseImage(&src);
     cvDestroyWindow("Components");
     cvReleaseImage(&dst);

     return 0;
 }