| Lossless Jpeg |
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| CATEGORIES ABOUT LOSSLESS JPEG | |
| graphics file formats | |
| lossless compression algorithms | |
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Lossless JPEG was developed as a late addition to JPEG in 1993, using a completely different technique from the lossy JPEG standard. It uses a predictive scheme based on the three nearest (causal) neighbors (upper, left, and upper-left), and Entropy coding is used on the prediction error. It is not supported by the standard Independent JPEG Group Libraries , and was never widely adopted. JPEG-LS was developed with the aim of providing a low complexity "near lossless" image compression standard that could be able to offer better compression efficiency than lossless JPEG. Part 1 of this standard was finalized in 1999; and when released, Part 2 of this standard will introduce extensions such as and context-based coding of the residuals. Most of the low complexity of this technique comes from the assumption that prediction residuals follow a two-sided Geometric Distribution (also called a discrete Laplace Distribution ) and from the use of Golomb -like codes, which are known to be approximately optimal for geometric distributions. Besides near lossless compression, JPEG-LS also provides a lossy mode where the maximum absolute error can be controlled by the encoder. Compression for JPEG-LS is generally much faster than JPEG 2000 and much Better than the original lossless JPEG standard. JPEG 2000 includes a lossless mode based on a special integer Wavelet filter (biorthogonal 3/5). JPEG 2000's lossless mode runs more slowly and has often worse Compression Ratios than JPEG-LS on artificial and compound images {Link without Title} {Link without Title} . JPEG 2000 fares better than the UBC implementation of JPEG-LS on digital camera pictures. JPEG 2000 is also scalable, progressive, and more widely supported. EXTERNAL LINKS
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