Entropy-based detection of microcalcifications in wavelet space

In this paper we present a method for the detection of microcalcifications in digital mammographic images. Our approach is based on the wavelet transform, but differently from other techniques proposed in the literature, the detection is directly accomplished into the wavelet domain and no inverse transform is required. After a preliminary denoising pass, microcalcifications are separated from background tissue. This is performed by exploiting information gained through evaluation of Renyi's entropy at the different decomposition levels of the wavelet space. Experimental results achieved on the standard Nijmegen data set are shown and discussed.