Cheng Cho-Chun, Peng Guan-Ju, Hwang Wen-Liang
Institute of Information Science, Academia Sinica, Nankang, Taipei, Taiwan. R.O.C.
IEEE Trans Image Process. 2009 Jan;18(1):52-62. doi: 10.1109/TIP.2008.2007067.
Performing optimal bit-allocation with 3-D wavelet coding methods is difficult because energy is not conserved after applying the motion-compensated temporal filtering (MCTF) process and the spatial wavelet transform. The problem cannot be solved by extending the 2-D wavelet coefficients weighting method directly and then applying the result to 3-D wavelet coefficients, since this approach does not consider the complicated pixel connectivity that results from the lifting-based MCTF process. In this paper, we propose a novel weighting method, which takes account of the pixel connectivity, to solve the problem and derive the effect of the quantization error of a subband on the reconstruction error of a group of pictures. We employ the proposed method on a 2-D + t structure with different temporal filters, namely the 5-3 filter and the 9-7 filter. Experiments on various coding parameters and sequences show that the proposed approach improves the bit-allocation performance over that obtained by using the weightings derived without considering the pixel connectivity in the MCTF process.
使用三维小波编码方法执行最优比特分配很困难，因为在应用运动补偿时域滤波（MCTF）过程和空间小波变换后，能量不守恒。该问题无法通过直接扩展二维小波系数加权方法然后将结果应用于三维小波系数来解决，因为这种方法没有考虑基于提升的MCTF过程所导致的复杂像素连通性。在本文中，我们提出了一种新颖的加权方法，该方法考虑了像素连通性，以解决该问题并推导子带量化误差对一组图像重建误差的影响。我们将所提出的方法应用于具有不同时域滤波器（即5-3滤波器和9-7滤波器）的二维+t结构。在各种编码参数和序列上进行的实验表明，与使用在MCTF过程中未考虑像素连通性而得出的加权相比，所提出的方法提高了比特分配性能。
