Image Compression using Alpha-Molecules

This paper describes a simple and efficient method of image compression using Alpha-molecules and Huffman coding technique. Image compression using Wavelet transform, Curvelet transform and Contourlet transform followed by Huffman coding exists in the literature. The work in this paper is proposed using Shearlet transform which has not been done yet. Various biomedical images of MRI of different parts of body such as lungs, shoulder, cardiac and brain are compressed using transform based coding. Wavelet and its variants such as Curvelet, Contourlet and Shearlet are used for transformation. The approximation and detail coefficients being extracted are processed for coding followed by decoding and inverse transformation. A comparative analysis is drawn between various transforms on the basis of various quantitative measures such as PSNR (Peak Signal to Noise ratio), MSE (Mean Square error), AD (Average Difference), NAE (Normalized Absolute error).