DCT information recovery of erroneous image for MPEG-2

Abstract

In this paper, a novel error concealment technique based on the discrete cosine transform ( D m coefficients recovery is presented, and the estimating method of DC and low frequency coefficients is described in detail. The proposed technique makes full use of the neighboring information around the missing blocks, instead of only considering a row of pixels. The proposed algorithm is simple and is applicable to any unitary block-transform and is very effective for recovering the DC and low frequency coefficients. Simulation results show that the quality of recovered images is significantly improved in different marcoblock loss (MB) rate. ABSTRACTIn this paper, a model-based algorithm is described to segment the pectoral muscle in the mammograms. Afier the mammogram has been preprocessed, a set of ROI with different sizes is applied on it, in each of which, an iterative thresholding technique is used to gain an optimal threshold correspondingly. All the thresholds compose the threshold curve and e curve, which the optimal threshold of the mammogram could be extracted by. Finally, a twice line fitting and polygon approaching technique is carried out to refine and approach the edge curve of the pectoral muscle, which has been partly segmented by the thresholding. About 60 mammograms have been used to evaluate the proposed algorithm with satisfactory result reached.