This paper presents a novel technique to increase

the quality of medical images based on Histogram

Equalization. In the proposed method first we have

applied a noise reduction method and then we apply

some suitable preprocessing on histogram of the

medical images and after that histogram equalization

has been applied on the new histogram. Our proposed

method in despite of its simplicity has better results in

compare to other usual methods based on histogram

equalization. The quality of resulted images after

applying our proposed methods has been tested on a

database (medical images) with a confirmed criterion

by viewer. Also we have considered a mathematical

criterion for comparing our proposed algorithm with

other available methods for contrast enhancement.

Results show the better efficiency of the proposed

method.