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Run-Length and Dictionary Coding: Information Theory Results (III)
Published in Yun Q. Shi, Huifang Sun, for Multimedia Engineering, 2017
A set of color test images from the JPEG standards committee was used for performance comparison. The luminance component (Y) is of resolution 720 × 576 pixels, while the chrominance components (U and V) are of 360 × 576 pixels. The compression ratios calculated are the combined results for all the three components. The following observations have been reported: When quantized in 8 bits/pixel, the compression ratios vary much less for multilevel images than for bilevel images, and are roughly equal to 2.When quantized with 5 bits/pixel down to 2 bits/pixel, compared with the lossless JPEG, the JBIG achieves an increasingly higher compression ratio, up to a maximum of 29%.When quantized with 6 bits/pixel, JBIG and lossless JPEG achieve similar compression ratios.When quantized with 7–8 bits/pixel, the lossless JPEG achieves a 2.4%–2.6% higher compression ratio than JBIG.
Lossless Compression
Published in Jerry D. Gibson, The Communications Handbook, 2018
The JBIG algorithm proposed by the joint bilevel image experts group defines a standard for lossless image compression. The algorithm is mainly designed for bilevel or binary data such as facsimile, but can also be used for image data with up to 256 b/pixel by encoding individual bit planes. The algorithm performs best for data up to 6 b/pixel, and beyond 6 b, other algorithms such as lossless JPEG give better performance. JBIG is described in more detail in the next chapter.
Binary medical image compression using the volumetric run-length approach
Published in The Imaging Science Journal, 2019
Erdoğan Aldemir, Gulay Tohumoglu, M. Alper Selver
Up-to-date binary image compression standards such as JBIG [21,22] and JBIG2 [23], quad-tree [24], CALIC [8] and RLE [25–27] are used in telemedicine protocols and medical storage/archiving systems. On the one hand, aforementioned techniques achieve a considerable result in binary data, but on the other hand, since these general standards are not specifically designed to remove redundancy in binary medical data, there still exists a significant redundant data that cannot be achieved by these standards. Moreover, existing compression systems utilize only intra-slice correlation to attain the pixel redundancy [28]. The volumetric methods have also drawbacks in terms of the complexity of the vector representation.