Aliasing Reduction via Frequency Roll-Off for Scalable Image/Video Coding

The extracted low resolution video from a motion compensated 3-D subband/wavelet scalable video coder is unnecessarily sharp and sometimes contains significant aliasing, compared to that by the MPEG4 low pass filter. In this paper, we propose a content adaptive method for aliasing reduction in subband/wavelet scalable video coding. We try to make the low resolution frame (LL subband) visually similar to that of the MPEG4 decimation filter through frequency roll-off. Scaling of the subbands is introduced to make the variances of the subbands comparable in these two cases. Thanks to the embedded properties of the EZBC coder, we can achieve the needed scaling of energies in each subband by sub-bitplane shift in the extractor and coefficient scaling in the decoder. An analysis is presented for the relationship between sub-bitplane shift and scaling, which shows that our selected sub-bitplane shift works well for high to medium bitrates. Two different energy-matching structures, i.e. a dya...

• Type: Journal
• Year: 2008
• Where: TCSV
• Authors: Yongjun Wu, John W. Woods
• Keywords: Low Resolution, Scalable Video, Sub-bitplane Shift, TCSV 2008