Proposed are two novel composite spatial orientation trees for SPIHT-based colourimage codecs to link wavelet coefficients of three colour planes together. The simulation results show the improved performance of the ...
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Proposed are two novel composite spatial orientation trees for SPIHT-based colourimage codecs to link wavelet coefficients of three colour planes together. The simulation results show the improved performance of the proposed methods over the conventional wavelet-based colour image coding techniques.
In this paper, a new adaptive vector quantisation with variable block size based on orthogonal polynomials is proposed for colourimagecoding. The input colourimage is partitioned into fixed larger block sizes and t...
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In this paper, a new adaptive vector quantisation with variable block size based on orthogonal polynomials is proposed for colourimagecoding. The input colourimage is partitioned into fixed larger block sizes and the homogeneity/complexity of the local region is tested with the mean-normalised variance classifier. The homogeneous regions are encoded with fixed larger blocks and the complex regions are further divided into smaller block sizes for encoding as it gives the wealth of low-level information such as the high detail and high number of contrast edges. The integer-based orthogonal polynomials transform is then applied on the variable block sizes utilising the inter-correlation property of individual colour planes and interactions among the colour planes so as to reduce the vector dimension and hence the less computational cost. The proposed technique generates two dynamic codebooks and two backup codebooks adaptively and use rate-distortion cost criteria to encode both the homogeneous and complex regions separately. Since the proposed method encodes all the three colour components in single pass, the colourimage encoding time is slightly higher than that of grey scale imagecoding but in contrast to three times in the existing colour image coding techniques.
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