Compression of mixed video and graphics images for TV systems

The diversity in TV images has augmented with the increased application of computer graphics. In this paper we study a coding system that supports both the lossless coding of such graphics data and regular lossy video compression. The lossless coding techniques are based on runlength and arithmetical coding. For video compression, we introduce a simple block predictive coding technique featuring individual pixel access, so that it enables a gradual shift from lossless coding of graphics to the lossy coding of video. An overall bit rate control completes the system. Computer simulations show a very high quality (SNR greater than or equal to 50 dB) with a compression factor between 2-3.