5. The method according to claim 2, wherein said step of extracting predetermined features comprises: determining, for each region in the digital mammogram of predetermined size corresponding to the location of each pixel of the second binary image, at least two of the area, contrast and background value of a signal within each said region.
5. The method according to claim 2, wherein said step of extracting predetermined features comprises: determining, for each region in the digital mammogram of predetermined size corresponding to the location of each pixel of the second binary image, at least two of the area, contrast and background value of a signal within each said region. 6. The method according to claim 5, wherein said identifying step comprises: performing an area versus contrast thresholding test to determine, for each signal for which features are extracted, whether that signal corresponds to a false positive signal, and if so, removing from said second binary image that pixel identifying the location of said false positive signal by setting the value of that pixel in the second binary image to a predetermined value.