Transforming the Image - cvPyrDown()
cvPyrDown is a wrapper image that allocates the output image and perform transformations we want.- Performs a gaussian smooth. Use it for reducing an image by a factor of 2
IplImage* doPyrDown(IplImage* in, int filter = IPL_GAUSSIAN_5x5){
//make sure image is divisible by two
assert(in->width%2==0 && in->height%2==0);
IplImage* out = cvCreateImage(
cvSize(in->width/2, in->height/2),
in->depth,
in->nChannels);
cvPyrDown(in, out);
return(out);
}
int main(int argc, char** argv){ //from the camera CvCapture* capture = cvCreateCameraCapture(0); //from a video file //cvCreateFileCapture(...); assert(capture != NULL); //rest of program cvNamedWindow("Webcam", CV_WINDOW_AUTOSIZE); cvNamedWindow("Modified", CV_WINDOW_AUTOSIZE); IplImage* frame; IplImage* mod; while(1) { frame = cvQueryFrame(capture); if(!frame) break; mod = doPyrDown(frame); cvShowImage("Webcam", frame); cvShowImage("Modified", mod); cvReleaseImage(&mod); char c = cvWaitKey(37); if(c == 27) break; } cvReleaseCapture(&capture); cvDestroyWindow("Webcam"); cvDestroyWindow("Modified");}output:
