Wavelet Packet Compression of Medical Images

Abstract

Tolba, A. S., Wavelet Packet Compression of Medical Images, Digital Signal Processing 12 (2002) 441–470 The increasing need for efficient image storage and transmission in hospitals imposes heavy requirements on the design of picture archiving and communication systems. Thus new methods are needed for efficient image compression. Recent reviews of wavelets in biomedical applications showed that wavelets should be used with caution and that a particular solution should always be motivated by the problem itself. This study discovers the best design parameters for a data compression scheme applied to medical images of different imaging modalities. The proposed technique aims at reducing the transmission cost while preserving the diagnostic integrity. By selecting the wavelet packet's filters, decomposition level and subbands that are better adapted to the frequency characteristics of the image, one may achieve better image representation in the sense of lower entropy or minimum distortion. Experimental results show that the selection of the best parameters has a dramatic effect on the data compression rate of medical images. Statistical significance tests were performed on the experimental measures to conduct the most suitable wavelet shape for each imaging modality. Image quality measures are used to evaluate the performance of different wavelet filters for different imaging modalities. Image resolution is found to have a remarkable effect on the compression rate.