A Multiscale Morphological Approach to Local Contrast Enhancement for Ultrasound Images

A scheme for enhancing local contrast of ultrasound images based on multiscale morphology is presented in this paper. The conventional theoretical concept of local contrast enhancement using mathematical morphology has been applied in the field of ultrasound image processing. The main idea is to preserve speckle region unchanged and enhance tissue boundaries. The criterion of speckle region is defined from a similarity value obtained from histogram matching between the histogram in the processing window and a reference one derived from a speckle area. The intensity values of the scale-specific features of tissue boundaries area in the image extracted using multiscale top hat transformation are modified for achieving local contrast enhancement. Locally enhanced features are combined to reconstruct the final enhanced image. The proposed approach has been applied on a set of ultrasound images for testing its response and the result has been compared with that of other standard methods for getting performance.