10 January 1997 Block-based DCT and wavelet selective coding for arbitrarily shaped images
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Proceedings Volume 3024, Visual Communications and Image Processing '97; (1997); doi: 10.1117/12.263277
Event: Electronic Imaging '97, 1997, San Jose, CA, United States
Images usually have quite different properties place by place. This variation of local properties may affect the coding efficiency when utilizing a fixed coding method. In this paper, a new coding method which selects discrete cosine transform (DCT) or wavelet transform (WLT) block by block adaptively according to the local properties of the image to achieve high coding efficiency, is proposed. A separable WLT, which gives higher coding efficiency and can be treated in the same manner as DCT, is proposed to simplify the hardware/software implementation. And an adaptive scanning method associated with the separable WLT, which achieves high coding efficiency by scanning the corresponding coefficients with large values across the resolution first to shorten the zero-run, is also proposed. Furthermore, for coding of arbitrary-shaped images with block-based DCT and WLT, a new padding technique based on the concept of making boundary blocks smooth is proposed. These new coding methods are verified through the simulation in comparison with the MPEG-4 verification model. The simulation results show the improvement of PSNR up to 2 dB.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Zhixiong Wu, Toshifumi Kanamaru, "Block-based DCT and wavelet selective coding for arbitrarily shaped images", Proc. SPIE 3024, Visual Communications and Image Processing '97, (10 January 1997); doi: 10.1117/12.263277; https://doi.org/10.1117/12.263277

Image compression


Wavelet transforms

Discrete wavelet transforms

Image segmentation


Image resolution


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