摘要
首先根据当前运动图象压缩的国际标准 ,讨论了极低码率下的编码问题 ,然后介绍了 Matching Pursuit在该领域中的应用 ,其具体过程是利用二维 Gabor函数字典对帧间预测差值进行 Matching Pursuit[1 ] ,这样能获得低码率下更高的压缩比和更好的效果 ,而且由于函数字典不是基于块的 ,因此消除了在低码率下 DCT变换的方块效应 .此外 ,在进行帧间预测差值编码时 ,是从能量最集中的区域开始 ,逐渐分配比特 。
After reviewing some international recommendations for video com pression, the application of Matching Pursuit on video compression at very low b it rate is introduced. This algorithm decomposes the signal into linear expansio ns of waveforms using an overcomplete basis of Gabor functions. With adapting Ma tching Pursuit to the motion residual, a substantial improvement in both PSNR an d perceived visual quality can be gotten. The dictionary which is not block-bas ed can reduce block distortions compared with the low bit rate DCT systems. When coding motion residual, bits are assigned progressively to high energy areas in the motion residual. Thus the decoded image can show the areas where motion cha nges quickly. Another advantage is the flexible choice of dictionary.
出处
《中国图象图形学报（A辑）》
CSCD
2000年第7期597-602,共6页
Journal of Image and Graphics
