1. A method comprising: illuminating an object with patterns of a plurality of light sources, the patterns including a first pattern in which a first light source of the light sources is on and a second pattern in which the first light source is off; capturing a plurality of images of the object at a camera while illuminating the object with corresponding ones of the patterns, wherein each of the light sources is off for at least one of the plurality of images and on for at least one of the plurality of images; determining a min image that is a per-pixel minimum of all of the images for which the first light source is on; determining a max image that is a per-pixel maximum of all of the images for which the first light source is off; computing a difference image that is the per-pixel unsigned saturated subtract operation of the max image subtracted from the min image; analyzing glints in the captured plurality of images; and mapping a glint in the difference image to the first light source.