1. A method for detecting the laterality of a mammogram image, the method comprising: receiving a mammogram image; downsampling the mammogram image; performing a normalization process on the mammogram image; applying a probabilistic Hough transform (PHT) to a right half and a left half of the image to generate a number of right PHT lines in the right half of the image and to generate a number of left PHT lines in the left half of the image; and comparing the number of right PHT lines with the number of left PHT lines to determine a laterality of the mammogram image.