DocumentCode :
2879969
Title :
Postprocessing in block-based video coding based on a quantization noise model
Author :
Moon, Ki Woong ; Jang, Ick Hoon ; Kim, Nam Chul ; Kim, Tae Sik
Author_Institution :
Laboratory for 3G Handsets, Mobile Handsets Com., LG Electronics Inc., Anyang 431-080, Korea
Volume :
4
fYear :
2002
fDate :
13-17 May 2002
Abstract :
In this paper, we propose a postprocessing method based on a quantization noise model with some assumptions in wavelet domain to reduce the blocking and ringing artifacts in block-coded video sequences. The quantization noise is considered as the sum of the blocking noise and the remainder noise including ringing noise. Since the one-dimensional (1-D) wavelet transform (WT) used in this paper represents a regularized differentiation, the blocking noise which is a gray level discontinuity at each block boundary appears as an impulse. We model the impulse as the blocking noise in wavelet domain and reduce it by estimating and weakening the strength of each blocking noise component that appears as an impulse at the block boundary in wavelet domain. The impulse strength estimation is performed using median filter, quantization parameter (QP), and local activity. The remainder noise, which is considered as a white Gaussian noise at non-edge pixels, then is reduced by soft-thresholding. Experimental results show that the proposed method yields better performance over verification model (VM) post-filter in MPEG-4 for all test sequences of various compression ratios.
Keywords :
IEC; ISO standards; PSNR; Pixel;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Acoustics, Speech, and Signal Processing (ICASSP), 2002 IEEE International Conference on
Conference_Location :
Orlando, FL, USA
ISSN :
1520-6149
Print_ISBN :
0-7803-7402-9
Type :
conf
DOI :
10.1109/ICASSP.2002.5745456
Filename :
5745456
Link To Document :
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