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Your search keyword '"Ying-Wen Chang"' showing total 2 results
Start Over Author "Ying-Wen Chang" Topic electronic data processing
2 results on '"Ying-Wen Chang"'

1. An Efficient DCT Filter Using Four Adjacent Shift Blocks.

Author

Ying-Wen Chang and Yen-Yu Chen

Subjects
DISCRETE cosine transforms, FILTERS (Mathematics), BIT rate, COMPUTER algorithms, COMPUTER simulation, ELECTRONIC data processing
Abstract

Blocking effect is the major drawbacks in DCT-based codec at low bit-rate. This kind of degradation probably will affect the judgment of a final user. In this paper, a powerful post-processing filter is proposed in DCT frequency domain. The proposed algorithm uses a shift block within four adjacent DCT blocks to reduce computational complexity. By slightly modifying several DCT coefficients in the shift block, the artifacts that result from quantized and de-quantized process are alleviated. In our simulation results, our scheme can take best quality in both objective and subjective metrics. [ABSTRACT FROM AUTHOR]

Published
2007

2. Novel artifact removal algorithm in the discrete cosine transform domain.

Author

Ying-Wen Chang and Yen-Yu Chen

Subjects
*VISUAL perception, *COMPUTATIONAL complexity, *VISUAL discrimination, *ELECTRONIC data processing
Abstract

The blocking effect is the major drawback in discrete cosine transform (DCT)-based codecs at low bit rates. When a high compression ratio is required, boundaries between adjacent image blocks become visible. This kind of degradation probably will affect the judgment of an end user. In this work, a four-neighboring-block zero-masking technique is proposed in the DCT frequency domain. The proposed algorithm uses a shift block within four adjacent DCT blocks to reduce computational complexity. By slightly modifying several DCT coefficients in the shift block, the artifacts that result from quantization and dequantization processes are alleviated. The simulation results show that both visual perception and objective image quality are noticeably improved. [ABSTRACT FROM AUTHOR]

Published
2008
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