1. A method for creating a mask isolating a region of interest in an image and deleting information in said image peripheral to said region of interest, comprising the steps of: a) obtaining a digital first image containing said region of interest, said region of interest represented by pixels having pixel values; b) defining a first closed curve forming a perimeter around said region of interest in said first image; c) creating a second image comprising a plurality of pixels, said second image having a boundary corresponding to at least a portion of said first image, wherein the first closed curve around said region of interest in said first image is represented in said second image as a matching second closed curve within said boundary in said second image; d) assigning all pixels in said second image on said boundary and peripheral to said second closed curve with a first pixel value and assigning all pixels in said second image within the region bounded by said second closed curve a second pixel value, and e) saving said second image with the pixel values assigned as in step (d) as a mask, wherein application of said mask to said first image deletes areas peripheral to said region of interest and leaves pixel values for said region of interest undisturbed.