How to calculate the distance between two GMMs in OpenCV?

Question

I am training two GMMs in OpenCV, each with 4 components. One GMM is trained using all points from the foreground of an image and another is trained using all points in the background. I want to find out how close are the two GMMs to each other in order to get an idea on how close are the background colours to the foreground colours.

Any ideas on how I can go about this problem? The popular distance measures I see (KL, Mahalanobis etc.) are for single variable normal distributions. How can I extend this to GMMs trained on RGB values of each pixel?

Answer 1

Because gaussian mixture model consists of a set of weighted gaussians, you can find distance between centers of nearest gaussuans of two models. But this is not absolutely correct approach, because of probabilistic nature of model. It'll be much better to look at probabilities of both models for given value.