Histogram-modified local contrast enhancement for mammogram images

Abstract

Early detection of breast cancer in the mammograms is essential in the field of medicine. Contrast enhancement of mammograms based on Histogram Equalisation (HE) is presented. The standard HE usually results in excessive contrast enhancement because of the lack of control on the level of enhancement. The Histogram-Modified Local Contrast Enhancement (HMLCE) is introduced in this paper to adjust the level of contrast enhancement, which in turn gives the resultant image a strong contrast and brings the local details for more relevant interpretation. It incorporates both histogram modifications as an optimisation technique and an LCE technique. This method is tested for Mias mammogram images. The performance of this method is determined using three parameters like Enhancement Measure (EME), Absolute Mean Brightness Error (AMBE) and Discrete Entropy (H). From these measures, the proposed technique provides better contrast enhancement while preserving the local information of the mammogram images.