Medical Image Contrast Enhancement via Wavelet Homomorphic Filtering Transform.

A novel medical image enhancement algorithm based on spatial domain is presented in this paper. The medical image is firstly divided into several sub-images under the dyadic wavelet scale analysis. As different directional sub-images can reflect different characteristics, at each level, different Butterworth homomorphic filtering functions are used in performing filtering of corresponding sub-band images to attenuate the low frequencies as well as amplify the high frequencies and a linear adjustment is carried out on the low frequency of the highest level. Later, the wavelet reconstruction course is utilized to get the final image. Experiments on magnetic resonance (MR) images of temporomandibular joint (TMJ) soft tissues have shown that our method can eliminate non-uniformity luminance distribution of medical images effectively and its performance is better than traditional Butterworth homomorphic filtering algorithm. [ABSTRACT FROM AUTHOR]