1. An adaptive filter for filtering noise from a low-light image, the adaptive filter comprising: a morphology filter for dilating an edge detected in the image, thereby dividing the image into a non-edge region and a dilated edge region; and a comparative filter for comparing a pixel in the non-edge region to a region surrounding the pixel and optionally replacing the pixel, based on a result of the comparison, with a new pixel derived at least in part from the region surrounding the pixel.