Two-Dimensional Wavelet and DCT Transforms Applied for Entropic Compression Improvement Using Digital Images

摘要

An image processing patent technique for the improvement of entropic compression with digital images has been presented. "Two-dimension wavelet transform" (2D-DWT), "two-dimension discrete cosine transform" (2D-DCT) and multi-resolution perfect reconstruction structures, with quincunx filter and grid are used for image processing and simulations using MATLAB, up to 2-level of analysis and synthesis. The possibility of suppressing the high and middle frequencies components in order to increase compression rates was considered. As a result, higher rates of entropic compression were obtained with the application of 2D-DCT after 2D-DWT in the sub-images generated from the multiresolution perfect reconstruction structures. High quality reconstructed images were obtained, even when high and middle frequencies components were suppressed.