Image Restoration Algorithm Based on Wavelet Domain Improved Hidden Markov Tree Model
Tingzhi Shen · Laser & Infrared · 2006
An image restoration algorithm based on improved hidden Markov tree(IHMT) model in the wavelet domain is proposed,faced with the edge blurring problem in image recovery.More cross-correlations of wavelet coefficients between two neighboring scales are captured in the IHMT model,which makes the statistical property of the real world images' wavelet coefficients are accurately characterized.In light of Bayesian framework of image restoration method,simplified IHMT model is used as a priori information of images in the wavelet domain,and regularization restriction is made to recover them.An approximate equivalence method is used to simplify the recovery equation with mixture densities into single density.Experimental results show that,the algorithm can effectively retrieve edge information of images,and the peak signal to noise ratio(PSNR) is improved significantly.