A method (100) is provided for characterizing a functionality of a flash (14) from at least one image (200) captured with a camera (12) using the flash (14). The method (100) includes: analyzing the image (200) by segmenting (106) the image (200) into at least one sub-region (206, 208), and applying a metric (108) to the sub-region (206, 208) to measure an image property within the sub-region (206, 208); and determining (110) the functionality of the flash (14) in response to a result of the applied metric.