In digital video and graphics, a means of compressing and storing digitized photographic images by reducing the amount of color information saved while retaining all the luminance information. The principle behind it is that human eyes more easily detect changes in luminance than changes in color. Despite its advantages, however, it can result in a loss of contrast between pixels and diminished definition. It is a video compression format supported by CD-i. Abbreviated DYUV. See also YUV.