1. A method of detecting faces in an image stream, the method comprising: receiving an acquired image from said image stream including one or more face regions; sub-sampling said acquired image at a specified resolution to provide a sub-sampled image; identifying one or more regions of said acquired image predominantly including skin tones by applying one of a number of filters to define said one or more regions of said acquired image predominantly including skin tones; calculating a corresponding integral image for at least one of said skin tone regions of said sub-sampled acquired image; applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions each having a given size and a respective location; and adjusting focus distance incrementally for each of multiple new acquired images at least until at least one candidate face region is detected.