学习OpenCV——Max_Area寻找最大区域

a. 二值化b. 得到轮廓的个数c. 将面积小于100的轮廓删除d. 将宽、高 比例小于1的轮廓删除e. 把面积最大的轮廓用红色框框画出来

#include "stdafx.h"#include "cv.h"#include "highgui.h"int main( int argc, char** argv ){IplImage* src;src=cvLoadImage("D:/Demo.jpg",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 n=-1,m=0;//n为面积最大轮廓索引，m为迭代索引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;n=m;}m++;//  CvScalar color = CV_RGB( rand()&255, rand()&255, rand()&255 );//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 k=0;*/int count=0;for( ; contour != 0; contour = contour->h_next ){count++;double tmparea=fabs(cvContourArea(contour));if (tmparea==maxarea /*k==n*/){CvScalar color = CV_RGB( 255, 0, 0);cvDrawContours( dst, contour, color, color, -1, 1, 8 );}/*k++;*/}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;}