blobcentre.cpp

opencv codes in C++ (linux and eclipse)

//c++ opencv code for blob detection and marking blob centre 
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"
#include "BlobResult.h"
#include "BlobExtraction.h"
#include "Blob.h"
#include "cvaux.h"
#include <stdio.h>

IplImage  *image, *gray, *dst;
int main( int argc, char **argv)
{
    CvFont dfont;
    float hscale      = 0.5f;
    float vscale      = 0.5f;
    float italicscale = 0.0f;
    int  thickness    = 2;
    char text[255]    = "";
	
    cvInitFont (&dfont, CV_FONT_HERSHEY_SIMPLEX , hscale, vscale, italicscale, thickness, CV_AA);
	//capture video
	CvCapture* capture = cvCaptureFromFile("output.avi");
	//created 4 window to display images
    cvNamedWindow("Capture", 0);
    cvNamedWindow("Result", 0);
    cvNamedWindow("Foreground", 0);
    
    //print error if it doesnt capture image 
    if(!capture)
    {
        fprintf( stderr, "ERROR: capture is NULL \n" );
        getchar();
        return -1;
    }
    // query the frame and save it in image
    IplImage* image = cvQueryFrame(capture);
    CvBGStatModel* bg_model;
    //gaussian background subtraction
	bg_model =cvCreateGaussianBGModel( image );
	
	//loop through each frame
    for( int fr = 1;image; image = cvQueryFrame(capture), fr++ )
    {  
        if(!image)
        {
            fprintf( stderr, "ERROR: frame is null...\n" );
            getchar();
            break;
        }
		
		//created a copy of image in finalFrame
        IplImage* finalFrame = cvCloneImage(image);
		//update the image
        cvUpdateBGStatModel( image, bg_model );
         
               
        //created a copy of foreground in frame
        IplImage* frame = cvCloneImage(bg_model->foreground); 
        cvSmooth(frame, frame, CV_BLUR);
		cvErode(frame,frame,NULL,5);
		cvDilate(frame,frame,NULL,5);
		cvSmooth(frame, frame, CV_BLUR, 3, 3);
        cvPutText(bg_model->foreground, "foreground", cvPoint(20,400), &dfont, CV_RGB(255,255,255));
       
        
        
        IplImage* gsFrame = cvCreateImage(cvSize(image->width,image->height),IPL_DEPTH_8U,1);
       
        //converted the image to gray scale and save it in gsFrame
        cvCvtColor(image, gsFrame, CV_BGR2GRAY);
        
       	dst = cvCreateImage( cvSize( image->width, image->height ), IPL_DEPTH_8U, 3 );
		
	cvCopy( image, dst );
	cvPutText(dst, "original frame", cvPoint(20,400), &dfont, CV_RGB(255,255,255));

	//Blob detection------------------------------------------------
	CBlobResult blobs;
	blobs = CBlobResult( frame, NULL, 100, true );
	blobs.Filter( blobs, B_INCLUDE, CBlobGetArea(), B_LESS,5000);
	blobs.Filter( blobs, B_INCLUDE, CBlobGetArea(), B_GREATER,0);
	
	
	int blobnum = blobs.GetNumBlobs();
	CBlob blob;                                      
	CvPoint p1, p2; 
	
	for(int a = 0; a < blobnum; a++)
	{
		blob = blobs.GetBlob(a);
		p1.x = (int)blob.MinX();
		p1.y = (int)blob.MinY();
		p2.x = (int)blob.MaxX();
		p2.y = (int)blob.MaxY();
		
		int Meanx=(p1.x+p2.x)/2;
		int Meany=(p1.y+p2.y)/2;
		
	    printf("%d (%d,%d)", a, Meanx, Meany);
	    sprintf(text, "%d", (int)blob.area);
		
		
		cvLine( finalFrame, cvPoint(Meanx, Meany), cvPoint(Meanx, Meany), CV_RGB(153, 0 , 0), 4, 8, 0 );
		
		sprintf(text, "%d", (int)blob.area);
		cvPutText(finalFrame, text, cvPoint(p1.x, p2.y + 15), &dfont, CV_RGB(0,255,255));
		cvRectangle(finalFrame, p1, p2, CV_RGB( 204, 0, 0 ), 2, 8, 0 );
	}
	    
	
	cvShowImage( "Capture", dst );
	cvMoveWindow("Capture",0,0);
        cvShowImage( "Result", finalFrame );
        cvMoveWindow("Result", 500, 0);
        cvShowImage("Foreground", bg_model->foreground);
        cvMoveWindow("Foreground", 0, 400);
        cvSaveImage("output.jpg",finalFrame);
    	cvReleaseImage(&gsFrame);
        cvReleaseImage(&finalFrame);

		cvWaitKey(10);
    }
    
		cvWaitKey(0);
		cvReleaseCapture( &capture );
  		cvReleaseBGStatModel(&bg_model);
  	 
    cvDestroyWindow( "Capture" );
    cvDestroyWindow( "Result" );
    cvDestroyWindow( "Foreground" );
   
	cvReleaseImage( &image );
	cvReleaseImage( &gray );
	cvReleaseImage( &dst );
	cvDestroyAllWindows(); 

	return 0;
}