[OpenCV] Line counter using edge detection.

LineCounter.cpp

#include "opencv/cv.h"
#include "opencv/highgui.h"
#include <stdio.h>

void dy(IplImage* buf1, IplImage* out) {
	for (int x=0;x<buf1->width;x++) {
		for (int y=0;y<buf1->height;y++) {
			out->imageData[out->widthStep*y+x]=abs((uchar)buf1->imageData[buf1->widthStep*(y+1)+x]-(uchar)buf1->imageData[buf1->widthStep*y+x]);
		}
	}
}

void extract(IplImage* buf, IplImage* out) {
	for (int x=0;x<buf->width;x++) {
		for (int y=0;y<16;y++) { out->imageData[out->widthStep*y+x]=buf->imageData[buf->widthStep*(buf->height-120+y)+x]; }
	}
}

int count(IplImage* strip) {
	int cnt=0, out;
	for (int x=0;x<strip->width;x++) {
		for (int y=0;y<strip->height;y++) { cnt+=((uchar)strip->imageData[strip->widthStep*y+x])/255; }
	}
	if (cnt<5000) {
		if (cnt<4500) { out=0; }
		else { out=1; }
	}
	else { out=2; }
	return(out);
}

void comb(IplImage*a, IplImage*b) {
	for (int x=0;x<b->width;x++) {
		for (int y=0;y<16;y++) { a->imageData[a->widthStep*(a->height-120+y)+x]=b->imageData[b->widthStep*y+x]; }
	}
}

void main() {
	IplImage* img;
	CvCapture* cap=cvCaptureFromCAM(0);
	cvNamedWindow("Line Counter", 1);
	CvFont* font1=new CvFont;
	CvFont* font2=new CvFont;
	cvInitFont(font1, CV_FONT_HERSHEY_SIMPLEX, 0.5f, 1.0f, 0, 3, 8);
	cvInitFont(font2, CV_FONT_HERSHEY_SIMPLEX, 0.5f, 1.0f, 0, 2, 8);
	int val=0, axx=0, bxx=0;
	char text[8];
	for (;;) {
		img = cvQueryFrame(cap);
		if (!img) break;
		IplImage* gray1=cvCreateImage(cvSize(img->width, img->height), 8, 1);
		IplImage* edge1=cvCreateImage(cvSize(img->width, 16), 8, 1);
		cvCvtColor(img, gray1, 7);
		extract(gray1, edge1);
		dy(edge1, edge1);
		cvThreshold(edge1, edge1, 10, 255, CV_THRESH_BINARY_INV);
		val=count(edge1);
		if (val==0&&axx==0) { axx=1; }
		if (val==2&&axx==1) { axx=0; bxx++; }
		sprintf(text, "%i", bxx);
		comb(gray1, edge1);
		cvPutText(gray1, text, cvPoint(10, 160), font1, cvScalarAll(255));
		cvPutText(gray1, text, cvPoint(10, 160), font2, cvScalarAll(0));
		cvShowImage("Line Counter", gray1);
		if (cvWaitKey(5) > 0) break;
		cvReleaseImage(&gray1);
		cvReleaseImage(&edge1);
	}
}