A system for generating an on-screen display (OSD) is described. The on-screen display, which has a semitransparent background area, is overlaid on top of an image. The data which make up this image are stored in a buffer. An accumulator, connected to the buffer, is used to examine this data, and store information about it. An attached OSD module used the stored information to automatically adjust the semitransparent background of the OSD.