In an OpenCV application, how do I identify the source of memory leak and fix it?

Question

I have a memory leak in my OpenCV application. Its a medium size application with a dozon of classes and a few thousands lines of code. Somehow, I managed to produce a large

Answer 1

Not an answer, but a suggestion: Move from OpenCV C interface to C++. If properly used, it will minimize your chances for a leak, now and in the future. Its smart pointers embedded in the objects automatically free memory.

In the worst case, you'll have a performance penalty (too many allocs/deallocs), but those are easy to spot in a profiler.

The C++ interface is using

Mat intead of IplImage, 
Point instead of CvPoint, 
cv::function() instead of cvFunction. 

And you do not have to declare pointers to images:

Mat src = imread("myfile.jpg");
Mat gray; // note that I do not allocate it. 
// This is done automatically in the next functions
cv::cvtColor(src, gray, CV_BGR2GRAY);
imshow("Gray image", gray);
waitKey();

If you have some legacy code, or a third-party that uses the other interface, it's easy to convert back and forth:

Mat src(width, height, CV_8UC3);
IplImage* legacyImg;
legacyImg = &(IplImage)src;

Other datatypes (like CvPoint) are automatically converted. CvSeq is replaced by std::vector<T>