The LibJPEG-Turbo software

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Table of Contents > QUARC > License Information > Third-Party License Agreements

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The SIMD-accelerated JPEG library that is employed by the Image Compress, Image Decompress and Vision Write JPEG File blocks in QUARC is based on the libjpeg-turbo open-source software. This document replicates the background and license information from the README file that accompanied the libjpeg-turbo software. All references to "software" within the rest of this document refer only to the libjpeg-turbo software and not to QUARC itself.

Background

libjpeg-turbo is a JPEG image codec that uses SIMD instructions (MMX, SSE2, NEON, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, ARM, and PowerPC systems. On such systems, libjpeg-turbo is generally 2-6x as fast as libjpeg, all else being equal. On other types of systems, libjpeg-turbo can still outperform libjpeg by a significant amount, by virtue of its highly-optimized Huffman coding routines. In many cases, the performance of libjpeg-turbo rivals that of proprietary high-speed JPEG codecs.

libjpeg-turbo implements both the traditional libjpeg API as well as the less powerful but more straightforward TurboJPEG API. libjpeg-turbo also features colorspace extensions that allow it to compress from/decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.), as well as a full-featured Java interface.

libjpeg-turbo was originally based on libjpeg/SIMD, an MMX-accelerated derivative of libjpeg v6b developed by Miyasaka Masaru. The TigerVNC and VirtualGL projects made numerous enhancements to the codec in 2009, and in early 2010, libjpeg-turbo spun off into an independent project, with the goal of making high-speed JPEG compression/decompression technology available to a broader range of users and developers.

License

libjpeg-turbo is covered by three compatible BSD-style open source licenses.

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