1 November 1992 Image coding based on classified lapped orthogonal transform vector quantization
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Proceedings Volume 1818, Visual Communications and Image Processing '92; (1992) https://doi.org/10.1117/12.131467
Event: Applications in Optical Science and Engineering, 1992, Boston, MA, United States
Classified transform coding of images using vector quantization has proved to be an efficient technique. Transform vector quantization combines the energy compaction properties of transform coding and the superior performance of vector quantization. Classification improves the reconstructed image quality considerably because of adaptive bit allocation. Block transform coding of images, traditionally using DCT, produces an undesirable effect called the blocking effect. In this paper a classified transform vector quantization technique using the lapped orthogonal transform (LOT/VQ) is presented. Image blocks are transformed using the LOT and are classified into four classes based on their structural properties. These are further divided adaptively into subvectors depending on the LOT coefficient statistics as this allows efficient distribution of bits. These subvectors are then vector quantized. The LOT/VQ is an efficient image coding algorithm which also reduces the blocking effect significantly. Coding tests using computer simulation show the effectiveness of this technique.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Suresh Venkatraman, Jae Yeal Nam, and K. R. Rao "Image coding based on classified lapped orthogonal transform vector quantization", Proc. SPIE 1818, Visual Communications and Image Processing '92, (1 November 1992); doi: 10.1117/12.131467; https://doi.org/10.1117/12.131467

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