1. A method for removing undesired features in an image, the method comprising: converting the image from a spatial domain to a frequency domain to form a transformed image; applying a filter to the transformed image to form a filtered image in the frequency domain; converting the filtered image from the frequency domain back into the spatial domain to form a modified image, wherein an intensity of an undesired feature in the modified image is increased as compared to the intensity of the undesired feature in the image; and removing the undesired feature from the image using the modified image to form a processed image.