Subtraction of images for automatic determination of center of the radiation field

The present study consist in the development of an algorithm that allows corrections in variations of density caused by the heel effect in mammographic images. This method automatically determines the position of center of the radiation field and from this it calculates the intensity of radiation in each point of the image by determining the path that photons travel inside the target, correcting all the points of image according to excess or lack of radiation to which they were submitted. The traditional method to correct nonuniform illumination was also used to compare the efficiency of the proposed method in order to improve the quality of mammographic images.