Quick try at matching wave whitecaps with OpenCV

main.c

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

// A quick proof-of-concept by Louis St-Amour to scan for the white bits of waves
// in specific video files. Rather slow; each frame takes about 7 seconds (!)
// on a Core 2 Duo Unibody MacBook Pro.

IplImage* doPyrDown(IplImage* in, int filter) {
	// Best to make sure input 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, filter);
	return out;
}

IplImage* cvtHSV(IplImage* in) {	
	IplImage* out = cvCreateImage(
								  cvSize(in->width, in->height),
								  in->depth, in->nChannels);
	cvCvtColor(in,out, CV_BGR2HLS);
	return out;
}

int main (int argc, const char * argv[]) {
    //cvNamedWindow("H", CV_WINDOW_AUTOSIZE);
	cvNamedWindow("Preview", CV_WINDOW_AUTOSIZE);
	//cvNamedWindow("S", CV_WINDOW_AUTOSIZE);
	CvCapture* capture = cvCaptureFromFile(argv[1]);
	if (!capture) {
		return -1;
	}
	IplImage* frame = cvQueryFrame(capture); // Init the video read
	double total = cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
	//CvVideoWriter *writer = cvCreateVideoWriter(
//												argv[2], 
//												CV_FOURCC('A','V','C','1'), 
//												fps, cvGetSize(frame), 1);

	IplImage* hImage = cvCreateImage(cvSize(frame->width, frame->height), 
									 frame->depth, 1);
	IplImage* sImage = cvCreateImage(cvSize(frame->width, frame->height), 
									 frame->depth, 1);
	IplImage* addedImage = cvCreateImage(cvSize(frame->width, frame->height), 
										 frame->depth, 1);
	IplImage* binaryImage = cvCreateImage(cvSize(frame->width, frame->height), 
										  frame->depth, 1);
	IplImage* eroded = cvCreateImage(cvSize(frame->width, frame->height), 
									 frame->depth, 1);
	IplConvKernel* kernel = cvCreateStructuringElementEx(7, 7, 3, 3, CV_SHAPE_ELLIPSE, NULL);
	IplImage* dilated = cvCreateImage(cvSize(frame->width, frame->height), 
									  frame->depth, 1);
//	IplImage* output = cvCreateImage(
//									 cvSize(frame->width, frame->height),
//									 frame->depth, frame->nChannels);
//	IplImage* highlight = cvCreateImage(
//										cvSize(frame->width, frame->height),
//										frame->depth, frame->nChannels);
	unsigned int count = 0;
	do {
		//cvSplit(hsvImage, hImage, sImage, vImage, NULL);
		IplImage* hsvImage = cvtHSV(frame);
		
		cvSetImageCOI(hsvImage, 1);
		cvCopy(hsvImage, hImage, NULL);
		
		cvSetImageCOI(hsvImage, 2);
		cvCopy(hsvImage, sImage, NULL);
		
		cvAddWeighted(hImage, 0.3, sImage, 0.7, 0.0, addedImage);
		
		cvThreshold(addedImage, binaryImage, 105, 255, CV_THRESH_BINARY);
		cvErode(binaryImage, eroded, kernel, 3);
		cvDilate(eroded, dilated, kernel, 1);
		
		//cvSetZero(highlight);
//		cvSetImageCOI(highlight, 1);
//		cvCopy(dilated, highlight, NULL);
//		cvSetImageCOI(highlight, 2);
//		cvCopy(dilated, highlight, NULL);
//		cvSetImageCOI(highlight, 3);
//		cvCopy(dilated, highlight, NULL);
//		cvSetImageCOI(highlight, 0);
//		cvAddWeighted(highlight, 1.0, frame, 0.0, 0, output);
		//cvWriteFrame(writer, output);
		//IplImage* sResized = doPyrDown(output, IPL_GAUSSIAN_5x5);
		cvShowImage("Preview", dilated);
		
		printf("%5u/%f\n", count, total);
		
		#define BUFFER_SIZE 50
		char filename[BUFFER_SIZE];
		int n = snprintf(filename, BUFFER_SIZE, "export/%05u.png", count++);
		if (n < BUFFER_SIZE) {
			cvSaveImage(filename, dilated, NULL);
		}
		
		//cvReleaseImage(&sResized);
		cvReleaseImage(&hsvImage);
		//		
		//		char c = cvWaitKey(33);
		//		if (c==27) {
		//			break;
		//		}
		//		
		//		IplImage* vImage = cvCreateImage(cvSize(hsvImage->width, hsvImage->height), 
		//										 hsvImage->depth, 1);
		//		cvSetImageCOI(hsvImage, 3);
		//		cvCopy(hsvImage, vImage, NULL);
		//		IplImage* vResized = doPyrDown(vImage, IPL_GAUSSIAN_5x5);
		//		cvShowImage("S", vResized);
		//		cvReleaseImage(&vImage);
		//		cvReleaseImage(&vResized);
		//		
		//		
		//		cvReleaseImage(&hsvImage);
		//		
		char c = cvWaitKey(33);
		if (c==27) {
			break;
		}
	} while ((frame = cvQueryFrame(capture)) != NULL);
	//cvReleaseVideoWriter(&writer);
	cvReleaseImage(&sImage);
	cvReleaseImage(&eroded);
	cvReleaseImage(&dilated);
	//cvReleaseImage(&output);
	cvReleaseImage(&binaryImage);
	cvReleaseImage(&addedImage);
	//cvReleaseImage(&highlight);
	cvReleaseImage(&hImage);
	cvReleaseCapture(&capture);
	//cvDestroyWindow("H");
	cvDestroyWindow("Preview");
	//cvDestroyWindow("S");
    return 0;
}