Performance Evaluation of Wavelet and Contourlet Based Joint Medical Image Compression

Medical images are very crucial in providing a good diagnosis. It becomes imperative for these medical images to be processed. In this paper, we present a lossless image coder based on wavelet transform. The efficiency of wavelet transform in representing smooth edges present in medical images has been proved in literature. It has good localization properties in spatial and frequency domain. Ostu's global thresholding algorithm and Huffman encoding are applied to the wavelet transformed image. This encoding algorithm has been applied to CT, MRI images. The drawback in wavelet when representing edges has been overcome by the contourlet transform. The proposed joint image compression algorithm was applied to the contourlet transformed image. Experimental results indicate a comparative approach of the proposed system between the wavelet and the contourlet transformed image. The results obtained were appreciable in terms of compression ratio and PSNR values.