#ifdef _CH_
#pragma package <opencv>
#endif

#ifndef _EiC
#include "cv.h"
#include "highgui.h"
#include <stdio.h>
#include <stdlib.h>
#endif


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 )
 {
     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 );
   }
 }


 int main( int argc, char** argv )
 {
     char* filename = argc >= 2 ? argv[1] : (char*)"normal.jpg";
     CvRNG rng = cvRNG(-1);

     if( (img0 = cvLoadImage(filename,1)) == 0 )
         return 0;

     printf( "Hot keys: \n"
             "\tESC - quit the program\n"
             "\tr - restore the original image\n"
             "\tw or ENTER - run watershed algorithm\n"
            "\t\t(before running it, roughly mark the areas on the image)\n"
            "\t  (before that, roughly outline several markers on the image)\n" );

    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 );

     for(;;)
     {
         int c = cvWaitKey(0);

         if( (char)c == 27 )
             break;

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

         if( (char)c == 'w' || (char)c == '\n' )
         {
             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 );
             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 );
             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 );
             cvShowImage( "watershed transform", wshed );
             cvReleaseMemStorage( &storage );
             cvReleaseMat( &color_tab );
        }
     }

    return 1;
 }

 #ifdef _EiC
 main(1,"watershed.cpp");
 #endif