opencv实现分水岭算法

//  分水岭算法原理
//  

IplImage* marker_mask = 0;
IplImage* markers = 0;
//IplImage* img0 = 0, *img = 0, *img_gray = 0, *wshed = 0;
IplImage  *img_gray = 0, *wshed = 0;
CvPoint prev_pt = {-1,-1};

void on_mouse( int event, int x, int y, int flags, void* param )
{
	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 );
		cvLine( img, prev_pt, pt, cvScalarAll(255), 5, 8, 0 );
		prev_pt = pt;
		cvShowImage( "image", img );
	}
}

void CCVMFCView::OnWatershed()//分水岭
{
	int   flag=0;
	CvRNG rng = cvRNG(-1);

	img0 = cvCloneImage( workImg );         //  建立工作位图
	cvFlip(img0);

	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 );

	cvZero( marker_mask );
	cvZero( wshed );
	cvShowImage( "image", img );
	//  cvShowImage( "watershed transform", wshed );
	cvSetMouseCallback( "image", on_mouse, 0 );

	m_ImageType=-3;
	for(;;)
	{
		int c = cvWaitKey(0);

		if( c == 27 ) {
			if (!flag) {                    //  未加标记
				wshed = cvCloneImage( img0 );
			}
			break;
		}

		if( c == 'r' )
		{
			cvZero( marker_mask );
			cvCopy( img0, img );
			cvShowImage( "image", img );
		}

		if( c == 'w' || c == '\r' )
		{
			CvMemStorage* storage = cvCreateMemStorage(0);
			CvSeq* contours = 0;
			CvMat* color_tab;
			int i, j, comp_count = 0;
			//cvSaveImage( "wshed_mask.png", marker_mask );
			//marker_mask = cvLoadImage( "wshed_mask.png", 0 );
			cvFindContours( marker_mask, storage, &contours, sizeof(CvContour),
				CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );

			CvSeq* contourn = contours;
			int n;
			for (n=0; contourn != 0; contourn = contourn->h_next,n++) {
			}                               //  检查边界数
			if (n) {                        //  已作标记才进行处理             
				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) );
				}

				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 );  //  分水岭算法处理
					t = (double)cvGetTickCount() - t;
					//					printf( "exec time = %gms\n", 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 );
						uchar* dst = &CV_IMAGE_ELEM( wshed, uchar, i, j*3 );
						if( idx == -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 );  //  图像合成
				//				cvShowImage( "watershed transform", wshed );
				cvReleaseMemStorage( &storage );
				cvReleaseMat( &color_tab );
			}
			else {                          //  未加标记
				wshed = cvCloneImage( img0 );
			}
			cvCopy(wshed,workImg);
			cvFlip(workImg);

			CClientDC dc(this);
			StretchDIBits(dc.m_hDC,         //  刷新主窗口
				0,0,workImg->width,workImg->height,
				0,0,workImg->width,workImg->height,
				workImg->imageData,m_lpBmi,DIB_RGB_COLORS,SRCCOPY);
			flag=1;
		}
	}

	cvDestroyWindow( "image" );
	cvReleaseImage(&img0);
	cvReleaseImage(&img);
	cvReleaseImage(&img_gray);
	cvReleaseImage(&marker_mask);
	cvReleaseImage(&markers);

	cvFlip(wshed);
	m_dibFlag=imageReplace(wshed,&workImg);

	Invalidate();
}