Journal of Zhejiang University-SCIENCE A

, Volume 7, Issue 12, pp 2057–2062 | Cite as

An adaptive preprocessing algorithm for low bitrate video coding

  • Li Mao-quan 
  • Xu Zheng-quan 


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 words

Blocking artifact Quantization parameter Video preprocessing Bilateral filtering 

CLC number



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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Li Mao-quan 
    • 1
    • 2
  • Xu Zheng-quan 
    • 2
  1. 1.School of Electronic InformationWuhan UniversityWuhanChina
  2. 2.Multimedia Communication Engineering Center, State Key Laboratory of Information Engineering in Surveying, Mapping and Remote SensingWuhan UniversityWuhanChina

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