《学习OpenCV》练习3-7

#include "cv.h"
#include "highgui.h"
#include "stdio.h"

int main()
{
	IplImage* img = cvLoadImage( "homework_3-7.jpg" );
	IplImage* clone1, *clone2;
	IplImage* dst = cvCreateImage( cvGetSize(img), img->depth, 1 );	//创建一与原图像img大小和数据类型上一致、单通道的图像dst
	cvNamedWindow( "homework_3-7", CV_WINDOW_AUTOSIZE );
	cvSplit( img, dst, 0, 0, 0 );									//将img图像分割至dst，NULL，NULL，NULL中
//	cvShowImage( "homework_3-6", dst );
	clone1 = cvCloneImage( dst );									//克隆dst两次
	clone2 = cvCloneImage( dst );
	double max, min;
	cvMinMaxLoc( dst, &min, &max );									//将dst中的最小值、最大值分别写入min，max
	double thresh = ( max - min )/2;
	printf( "max = %f\nmin = %f\nthresh = %f\n", max, min, thresh );
	cvSet( clone1, cvScalar( thresh ));								//利用内联函数cvScalar为结构体CvScalar赋值thresh，利用cvSet将clone1的所有通道所有值设置为thresh
	cvZero( clone2 );
	cvCmp( dst, clone1, clone2, CV_CMP_GE );						//compare函数，比较dst与clone1，若dst>=clone1，则该点写入clone2
	cvSubS( dst, cvScalar( thresh/2 ), dst, clone2 );

	/*若dst < clone1的点，则dst减去thresh/2，即整个程序作用是将dst中的某点小于dst所有点的中间值/2，则该点减去该中间值thresh/2*/
	cvShowImage( "homework_3-7", dst );
	cvWaitKey( 0 );
	cvReleaseImage( &dst );

	return 0;
}