Optimal learning high-order Markov random fields priors of colour image

In this paper, we present an optimised learning algorithm for learning the parametric prior models for high-order Markov random fields (MRF) of colour images. Compared to the priors used by conventional low-order MRFs, the learned priors have richer expressive power and can capture the statistics of natural scenes. Our proposed optimal learning algorithm is achieved by simplifying the estimation of partition function without compromising the accuracy of the learned model. The parameters in MRF colour image priors are learned alternatively and iteratively in an EM-like fashion by maximising their likelihood. We demonstrate the capability of the proposed learning algorithm of highorder MRF colour image priors with the application of colour image denoising. Experimental results show the superior performance of our algorithm compared to the state-of-the-art of colour image priors in [1], although we use a much smaller training image set