Comparing two HOG descriptors vectors

I am using cv::HOGDescriptor (CPU version) to compute descriptors of two images. Then I would like to compare each window from the first image to each window of the other window of the other image and store location of the two windows that got the best score (nearest by L2 distance) and the distance between them. What is the best way to access all window descriptors received by ```cv::HOGDescriptor::compute(...)``` method? (This method is not documented, and fills one vector of floats which I don't understand how to interpreted)