We present and evaluate a novel idea for scalable lossy colour image coding with Matching Pursuit (MP) performed in a transform domain. The idea is to exploit correlations in RGB colour space between image subbands af...
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ISBN:
(纸本)9783642240850
We present and evaluate a novel idea for scalable lossy colour image coding with Matching Pursuit (MP) performed in a transform domain. The idea is to exploit correlations in RGB colour space between image subbands after wavelet transformation rather than in the spatial domain. We propose a simple quantisation and coding scheme of colour MP decomposition based on Run Length Encoding (RLE) which can achieve comparable performance to JPEG 2000 even though the latter utilises careful data modelling at the coding stage. Thus, the obtained image representation has the potential to outperform JPEG 2000 with a more sophisticated coding algorithm.
With desktop imaging devices becoming ubiquitous, effectively managing the images in large collections has become a challenge. The requirements for a modem imaging system now demand not only efficient storage (low bit...
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ISBN:
(纸本)0819439886
With desktop imaging devices becoming ubiquitous, effectively managing the images in large collections has become a challenge. The requirements for a modem imaging system now demand not only efficient storage (low bit rate coding), but also easy manipulation, indexing and retrieval of images. In this paper, we introduce a new method for colour image coding based on a visual appearance model of local colourimage patterns. The visual appearance of small image patterns is characterised by their spatial pattern, colour direction and local energy strength. To encode the local visual appearance, an approach based on vector quantisation (VQ) is introduced. A separate VQ is designed for the spatial pattern and colour direction respectively. It is shown that the method not only achieves good imagecoding results in terms of rate distortion criterion, it also enables content-based retrieval to be performed in the compressed domain easily and conveniently.
A novel colour image coding technique based on visual patterns is presented. Visual patterns, a concept first introduced by Chen and Bovik [1], are image blocks representing visually meaningful information. A method h...
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ISBN:
(纸本)0819431249
A novel colour image coding technique based on visual patterns is presented. Visual patterns, a concept first introduced by Chen and Bovik [1], are image blocks representing visually meaningful information. A method has been developed to extend the concept of visual patterns (originally developed for grayscale images) to colour image coding. A mapping criterion has been developed to map small image blocks to a set of predefined, universal visual patterns in a uniform colour space. Source coding and colour quantisation are applied to achieve efficient coding. Compression ratios between 40:1 and 60:1 (0.6 - 0.4 bpp) have been achieved;subjective as well as objective measures show that the new method is comparable to state-of-the-art techniques such as JPEG.
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