A non linear stretching image enhancement technique for microcalcification detection

Microcalcifications are small deposits of calcium accumulated in breast tissue. They are situated in higher gray level regions, with a very short gray level dynamic range. Besides, they have a small size with low contrast compared to the surrounding tissue. All these characteristics make micro-calcification´s preprocessing a crucial task. In this paper, we propose a new approach for enhancing microcalcifications in digitized mammogramdigitized mammogram, emphasizing corresponding gray level details. Accordingly, we propose an adaptive exponential function which creates a local modification of gray level to highlight details which are potential carriers of microcalcifications. We have applied the NLS twice: locally and globally. The performance of microcalcification´s enhancement method is developing using Farabi Digital Database of Screening Mammography (FDDSM). Performance results are given in terms of the Seconde-Derivative-like Measure of enhancement (SDME). Our proposed approach achieve 118 of the local NLS and 115 of the Global NLS.