OpenCV 를 사용 하여 분수령 알고리즘 을 실현 하 다

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

using namespace  std;

IplImage* marker_mask = 0;
IplImage* markers = 0;
IplImage* img0 = 0, *img = 0, *img_gray = 0, *wshed = 0;
CvPoint prev_pt = {-1,-1};
void on_mouse( int event, int x, int y, int flags, void* param )//opencv             
{
	if( !img )
		return;
	if( event == CV_EVENT_LBUTTONUP || !(flags & CV_EVENT_FLAG_LBUTTON) )
		prev_pt = cvPoint(-1,-1);
	else if( event == CV_EVENT_LBUTTONDOWN )
		prev_pt = cvPoint(x,y);
	else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON) )
	{
		CvPoint pt = cvPoint(x,y);
		if( prev_pt.x < 0 )
			prev_pt = pt;
		cvLine( marker_mask, prev_pt, pt, cvScalarAll(255), 5, 8, 0 );//CvScalar   ：double val[4] RGBA A=alpha
		cvLine( img, prev_pt, pt, cvScalarAll(255), 5, 8, 0 );
		prev_pt = pt;
		cvShowImage( "image", img);
	}
}

int main( int argc, char** argv )
{
	char* filename = argc >= 2 ? argv[1] : (char*)"fruits.jpg";
	CvMemStorage* storage = cvCreateMemStorage(0);
	CvRNG rng = cvRNG(-1);
	if( (img0 = cvLoadImage(filename,1)) == 0 )
		return 0;
	printf( "Hot keys: 
"
		"\tESC - quit the program
"
		"\tr - restore the original image
"
		"\tw or SPACE - run watershed algorithm
"
		"\t\t(before running it, roughly mark the areas on the image)
"
		"\t  (before that, roughly outline several markers on the image)
" );
	cvNamedWindow( "image", 1 );
	cvNamedWindow( "watershed transform", 1 );
	img = cvCloneImage( img0 );
	img_gray = cvCloneImage( img0 );
	wshed = cvCloneImage( img0 );
	marker_mask = cvCreateImage( cvGetSize(img), 8, 1 );
	markers = cvCreateImage( cvGetSize(img), IPL_DEPTH_32S, 1 );
	cvCvtColor( img, marker_mask, CV_BGR2GRAY );
	cvCvtColor( marker_mask, img_gray, CV_GRAY2BGR );//      RGB  3       R=G=B,     
	cvZero( marker_mask );
	cvZero( wshed );
	cvShowImage( "image", img );
	cvShowImage( "watershed transform", wshed );
	cvSetMouseCallback( "image", on_mouse, 0 );
	for(;;)
	{
		int c = cvWaitKey(0);
		if( (char)c == 27 )
			break;
		if( (char)c == 'r' )
		{
			cvZero( marker_mask );
			cvCopy( img0, img );//cvCopy（）      ，    img0  ，     
			cvShowImage( "image", img );
		}
		if( (char)c == 'w' || (char)c == ' ' )
		{
			CvSeq* contours = 0;
			CvMat* color_tab = 0;
			int i, j, comp_count = 0;

			//              ,              
			//             ，         
			//                    
			cvClearMemStorage(storage);
			cvFindContours( marker_mask, storage, &contours, sizeof(CvContour),
				CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
			cvZero( markers );
			for( ; contours != 0; contours = contours->h_next, comp_count++ )
			{
				cvDrawContours(markers, contours, cvScalarAll(comp_count+1),
					cvScalarAll(comp_count+1), -1, -1, 8, cvPoint(0,0) );
			}
			//cvShowImage("image",markers);
			if( comp_count == 0 )
				continue;
			color_tab = cvCreateMat( 1, comp_count, CV_8UC3 );//        
			for( i = 0; i < comp_count; i++ )　//       
			{
				uchar* ptr = color_tab->data.ptr + i*3;
				ptr[0] = (uchar)(cvRandInt(&rng)%180 + 50);
				ptr[1] = (uchar)(cvRandInt(&rng)%180 + 50);
				ptr[2] = (uchar)(cvRandInt(&rng)%180 + 50);
			}
			{
				double t = (double)cvGetTickCount();
				cvWatershed( img0, markers );
				cvSave("img0.xml",markers);
				t = (double)cvGetTickCount() - t;
				printf( "exec time = %gms
", t/(cvGetTickFrequency()*1000.) );
			}
			// paint the watershed image
			for( i = 0; i < markers->height; i++ )
				for( j = 0; j < markers->width; j++ )
				{
					int idx = CV_IMAGE_ELEM( markers, int, i, j );//markers      IPL_DEPTH_32S
					uchar* dst = &CV_IMAGE_ELEM( wshed, uchar, i, j*3 );//BGR          ,  j*3
					if( idx == -1 ) //     -1，         
						dst[0] = dst[1] = dst[2] = (uchar)255;
					else if( idx <= 0 || idx > comp_count )  //    
						dst[0] = dst[1] = dst[2] = (uchar)0; // should not get here
					else //    
					{
						uchar* ptr = color_tab->data.ptr + (idx-1)*3;
						dst[0] = ptr[0]; dst[1] = ptr[1]; dst[2] = ptr[2];
					}
				}
				cvAddWeighted( wshed, 0.5, img_gray, 0.5, 0, wshed );//wshed.x.y=0.5*wshed.x.y+0.5*img_gray+0      
				cvShowImage( "watershed transform", wshed );
				cvReleaseMat( &color_tab );
		}
	}
	return 1;
}