Television picture signal processing in which video and graphic signals are compressed using different compression algorithms stored in a same memory, and decompressed for display

Abstract

Field or frame memories are often used in television receivers for video signal processing functions, such as noise reduction and/or flicker reduction. Television receivers also have graphic features such as teletext, menu-driven control systems, multilingual subtitling, an electronic TV-Guide, etc. In a method of processing television picture signals including both video (VID) and graphic (GFX) information, the video and graphic signals are individually compressed in accordance with different (lossy and loss-less, respectively) compression algorithms (,), stored in the same field or frame memory (,), and decompressed (,) after processing (,). As such, a significant reduction of memory capacity is achieved without adversely affecting the graphics quality. The method is not only applicable to locally generated graphic signals (TXT,OSD) but also to graphic information which is detected (,) as being embedded in a received television signal.