JPEG 2000 Encoding Method for Reducing Tiling Artifacts

Masayuki HASHIMOTO  Kenji MATSUO  Atsushi KOIKE  

Publication
IEICE TRANSACTIONS on Information and Systems   Vol.E88-D   No.12   pp.2839-2848
Publication Date: 2005/12/01
Online ISSN: 
DOI: 10.1093/ietisy/e88-d.12.2839
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Image Processing and Video Processing
Keyword: 
JPEG 2000,  tiling artifacts,  rate control,  acceleration of coding process,  

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Summary: 
This paper proposes an effective JPEG 2000 encoding method for reducing tiling artifacts, which cause one of the biggest problems in JPEG 2000 encoders. Symmetric pixel extension is generally thought to be the main factor in causing artifacts. However this paper shows that differences in quantization accuracy between tiles are a more significant reason for tiling artifacts at middle or low bit rates. This paper also proposes an algorithm that predicts whether tiling artifacts will occur at a tile boundary in the rate control process and that locally improves quantization accuracy by the original post quantization control. This paper further proposes a method for reducing processing time which is yet another serious problem in the JPEG 2000 encoder. The method works by predicting truncation points using the entropy of wavelet transform coefficients prior to the arithmetic coding. These encoding methods require no additional processing in the decoder. The experiments confirmed that tiling artifacts were greatly reduced and that the coding process was considerably accelerated.