1. A computer-implemented method for determining an image, comprising: receiving a mask pattern; receiving a first image of at least a portion of a photo-mask corresponding to the mask pattern; and using the computer, determining a second image of at least the portion of the photo-mask in accordance with the first image and the mask pattern, wherein the second image is characterized by additional spatial frequencies than the first image; and wherein the mask pattern is characterized by spatial frequencies within a first band of frequencies, the first image is characterized by spatial frequencies within a second band of frequencies that is less than the first band of frequencies, and the second image is characterized by spatial frequencies within a third band of frequencies that is greater than the second band of frequencies.