main.c

#ifdef _CH_
#pragma package <opencv>
#endif

#include <cv.h>
#include <highgui.h>
#include <cvaux.h>
#include <stdio.h>
#include <time.h>

const char *VENTANA="Blob detection";

IplImage* imagen;
IplImage* imagen_color;
IplImage* smooth;
IplImage* threshold;
IplImage* open_morf;
IplImage* blobResult;
IplImage* img_contornos;
CvMoments moments;
CvHuMoments humoments;
CvSeq* contour;
CvSeq* contourLow;

int main( int argc, char** argv )
{
	srand ( time(NULL) );
	/**
	 * Init
	 **/
	printf( "Blob detection and feature extraction\n"
			"\tESC - quit the program\n"
			"\tDavid Millan Escriva | Damiles\n");

	/**
	 * Init images
	 **/

	//Check if user specify image to process
	if(argc >= 2 )
	{
		char* filename= argv[1];
		//load image  in gray level
		imagen=cvLoadImage(filename,0);
		//load image in RGB
		imagen_color=cvLoadImage(filename,1);
	}else{
		printf("Use:\n\t%s image\n",argv[0]);
		return 0;
	}	

	//Create needed images
	smooth= cvCreateImage(cvSize(imagen->width, imagen->height), IPL_DEPTH_8U, 1);
	threshold= cvCreateImage(cvSize(imagen->width, imagen->height), IPL_DEPTH_8U, 1);
	open_morf= cvCreateImage(cvSize(imagen->width, imagen->height), IPL_DEPTH_8U, 1);
	
	//Init variables for countours
	contour = 0;
	contourLow = 0;
	//Create storage needed for contour detection
	CvMemStorage* storage = cvCreateMemStorage(0);

	//Create window
	cvNamedWindow( VENTANA, 0 );


	//Smooth image
	cvSmooth(imagen, smooth, CV_GAUSSIAN, 3, 0, 0, 0);
	
	CvScalar avg;
	CvScalar avgStd;
	cvAvgSdv(smooth, &avg, &avgStd, NULL);
	printf("Avg: %f\nStd: %f\n", avg.val[0], avgStd.val[0]);
	//threshold image
	cvThreshold(smooth, threshold, (int)avg.val[0]-7*(int)(avgStd.val[0]/8), 255, CV_THRESH_BINARY_INV);
	//Morfologic filters
	cvErode(threshold, open_morf, NULL,1); 
	cvDilate(open_morf, open_morf, NULL,1); 
	//Duplicate image for countour
	img_contornos=cvCloneImage(open_morf);

	//Search countours in preprocesed image
	cvFindContours( img_contornos, storage, &contour, sizeof(CvContour),
			CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE, cvPoint(0, 0) );
	//Optimize contours, reduce points
	contourLow=cvApproxPoly(contour, sizeof(CvContour), storage,CV_POLY_APPROX_DP,1,1);
	
	//Show to user the 7 hu moments (features detected) we can use this for clasification
	printf("hu1\t\thu2\t\thu3\t\thu4\t\thu5\t\thu6\t\thu7\n");
	//For each contour found
	for( ; contourLow != 0; contourLow = contourLow->h_next )
	{
		CvScalar color = CV_RGB( rand()&200, rand()&200, rand()&200 );
		//We can draw the contour of object
		//cvDrawContours( imagen_color, contourLow, color, color, -1, 0, 8, cvPoint(0,0) );
		//Or detect bounding rect of contour	
		CvRect rect;
		CvPoint pt1, pt2;
		rect=cvBoundingRect(contourLow, NULL);
		pt1.x = rect.x;
            	pt2.x = (rect.x+rect.width);
            	pt1.y = rect.y;
            	pt2.y = (rect.y+rect.height);
		cvRectangle(imagen_color, pt1,pt2, color, 1, 8, 0); 
		
		//For calculate objects features we can use hu moments.
		//this calculate 7 features that are independent of position, size and orientation

		//First calculate object moments
		cvMoments(contourLow, &moments, 0);
		//Now calculate hu moments
		cvGetHuMoments(&moments, &humoments);

		//Show result.
		printf("%f\t%f\t%f\t%f\t%f\t%f\t%f\n", humoments.hu1, humoments.hu2, humoments.hu3, humoments.hu4, humoments.hu5, humoments.hu6, humoments.hu7);
	}

	cvShowImage(VENTANA, imagen_color);

	//Main Loop
	for(;;)
	{
		int c;

		c = cvWaitKey(10);
		if( (char) c == 27 )
			break;
		else if((char) c == '3')
			cvShowImage(VENTANA, threshold);
		else if((char) c=='1')
			cvShowImage(VENTANA, imagen);
		else if((char) c=='2')
			cvShowImage(VENTANA, smooth);
		else if((char) c=='4')
			cvShowImage(VENTANA, open_morf);
		else if((char) c=='r')
			cvShowImage(VENTANA, imagen_color);

	}

	cvDestroyWindow(VENTANA);

	return 0;
}