Video image quality may be improved by correcting exposure levels and/or
enhancing contrast amounts on each frame. One or more of the following
phases may be implemented: skin-color model building, face detecting,
exposure level correcting, and contrast enhancing. In a described
implementation, a Gaussian skin-color model is built for each image frame
during runtime. The Gaussian skin-color model is built with training
pixels that are selected responsive to a defined skin color range, which
is created offline from manually-selected skin pixels of multiple test
sequences. In another described implementation, each pixel of an image
frame is re-exposed using a ratio of contrast amount control variables
(CACVs). More specifically, a pixel may be converted to a corresponding
light intensity using a first CACV, and the corresponding light intensity
may be reconverted to a pixel using a second CACV to enhance the contrast
and possibly reduce fuzziness of the image frame.