Hadi Amirpour - Department of Electrical Engineering K. N. Toosi University of Technology Tehran, Iran
Bita Tarfiee - Department of Electrical Engineering K. N. Toosi University of Technology Tehran, Iran
Seyed Mohammad Shams - Department of Biomedical Engineering Islamic Azad University, South Tehran Branch Tehran, Iran

Breast cancer is one of the main causes of death for women and nowadays too much attention is placed on it. Cancer that’s diagnosed at an early stage, before it’s had the chance to get too big or spread is more likely to be treated successfully. A mammography exam, called a mammogram, aids in the early detection and diagnosis of breast diseases in women. However, in many cases, cancer is not detected easily by radiologist’s eyes and in order to improve image quality image-enhancement algorithms are proposed. In this paper, in order to enhance contrast of a mammogram a fuzzy based wavelet transform is introduced. First, a multiscale wavelet transform is obtained in four levels, and for denoising and improving quality of image fuzzy logic is applied to fourth level. Then, to enhance contrast of image wavelet coefficients in all scales are manipulated in a enhance factor. Simulation results show that proposed algorithm has better performance in various factors.

Mammograms; Wavelet transform; fuzzy logic; Contrast enhancement