1. A method comprising: receiving a color image comprising a plurality of color pixels; converting the color image to a monochromatic image comprising a plurality of monochromatic pixels; performing M erosion operations on the monochromatic image to generate an eroded monochromatic image, where M is equal to or greater than one; performing N dilation operations on the eroded monochromatic image to generate a mask image, where N is equal to or greater than one; identifying one or more regions of the mask image based on the mask image; and modifying regions of the color image corresponding to the identified regions of the mask image.