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Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering)  2006, Vol. 7 Issue (12): 15-    DOI: 10.1631/jzus.2006.A2057
    
An adaptive preprocessing algorithm for low bitrate video coding
LI Mao-quan, XU Zheng-quan
School of Electronic Information, Wuhan University, Wuhan 430079, China; Multimedia Communication Engineering Center, State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China
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Abstract  At low bitrate, all block discrete cosine transform (BDCT) based video coding algorithms suffer from visible blocking and ringing artifacts in the reconstructed images because the quantization is too coarse and high frequency DCT coefficients are inclined to be quantized to zeros. Preprocessing algorithms can enhance coding efficiency and thus reduce the likelihood of blocking artifacts and ringing artifacts generated in the video coding process by applying a low-pass filter before video encoding to remove some relatively insignificant high frequent components. In this paper, we introduce a new adaptive preprocessing algorithm, which employs an improved bilateral filter to provide adaptive edge-preserving low-pass filtering which is adjusted according to the quantization parameters. Whether at low or high bit rate, the preprocessing can provide proper filtering to make the video encoder more efficient and have better reconstructed image quality. Experimental results demonstrate that our proposed preprocessing algorithm can significantly improve both subjective and objective quality.

Key wordsBlocking artifact      Quantization parameter      Video preprocessing      Bilateral filtering     
Received: 15 March 2006     
CLC:  TN919.8  
Cite this article:

LI Mao-quan, XU Zheng-quan. An adaptive preprocessing algorithm for low bitrate video coding. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(12): 15-.

URL:

http://www.zjujournals.com/xueshu/zjus-a/10.1631/jzus.2006.A2057     OR     http://www.zjujournals.com/xueshu/zjus-a/Y2006/V7/I12/15

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