1. A method, comprising: illuminating a subject with light from a plurality of light sources, the plurality of light sources having distinct colors and configured to illuminate the subject from distinct locations; obtaining a multi-color image of the subject, the multi-color image comprising respective values corresponding to respective intensities of light of respective colors for each region of the subject; and determining a surface profile of the subject in accordance with the respective values corresponding to the respective intensities of light of the respective colors.