1. A method, comprising: calculating a face map comprising for each pixel of an input image a respective face probability value indicating a degree to which the pixel corresponds to a human face, wherein variations in the face probability values are continuous across the face map; ascertaining a skin map comprising for each pixel of the input image a respective skin probability value indicating a degree to which the pixel corresponds to human skin; and enhancing the input image with an enhancement level that varies pixel-by-pixel in accordance with the respective face probability values and the respective skin probability values; wherein the calculating, the ascertaining, and the enhancing are performed by a computer system.