自适应压扩量化帧内DPCM图象编码

自适应压扩量化帧内DPCM图象编码 INTRAFRAME DPCM PICTURE CODING WITH ADAPTIVE COMPANDING QUANTIZATION 萧自美 Xiao Zimei first-author 本文提出了一种用于电视信号帧内DPCM编码的自适应压扩量化新方法。图象编码器采用了一个与图象局部统计特性相适应的,按照局部活动性调节其大小的压扩因子和一种避免斜率过载的有效措施。与其它的量化方法主、客观性能相比较,表明了本方法的优点。对自然图象为3.5bits/pel,对分辩率测试卡为4bits/pel时,恢复图象与原图象相比较无明显差别。对于各种类型图象,大的恢复误差明显减少。 A new method using adaptive and compandng quantization is proposed, which can be used for intraframe DPCM coding of TV luminance signals. The proposed picture coder is executed by means of a companding factor, which can be adapted to local variations in image statistics by adjusting its numerical value according to the local activity, and a efficient measure of avoiding slop overload. An objective and subjective comparison involving various quantizing strategies demostrated the advantage of the proposed method. Reconstructed pictures in comparison with origlnal pictures for natural pictures with 3.Sbits/pel and for Resulation Chart with 4bits/pel are barey visible differences. Large reconstruction erros are reduced consideralbly for all kinds of pictures. 1986-04-01 2021-04-01 4