Semantic search

Jump to: navigation, search


Libjpeg
This package implements a JPEG codec (encoding and decoding) alongside various utilities for handling JPEG data. It is written in C and distributed as free software together with its source code under the terms of a custom permissive (BSD-like) free software license. The original variant is maintained and published by the Independent JPEG Group (IJG). Provision is made for supporting all variants of these processes, although some uncommon parameter settings aren't implemented yet. There has been no provision for supporting the hierarchical or lossless processes defined in the standard. A set of library routines is provided for reading and writing JPEG image files, plus two sample applications "cjpeg" and "djpeg", which use the library to perform conversion between JPEG and some other popular image file formats. The library is intended to be reused in other applications. In order to support file conversion and viewing software, there is considerable functionality beyond the bare JPEG coding/decoding capability; for example, the color quantization modules are not strictly part of JPEG decoding, but they are essential for output to colormapped file formats or colormapped displays. These extra functions can be compiled out of the library if not required for a particular application. There is also "jpegtran", a utility for lossless transcoding between different JPEG processes, and "rdjpgcom" and "wrjpgcom", two simple applications for inserting and extracting textual comments in JFIF files.

Forks

Libjpeg-turbo
libjpeg-turbo is a fork of libjpeg that uses SIMD instructions (MMX, SSE2, AVX2, Neon, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, Arm, and PowerPC systems, as well as progressive JPEG compression on x86 and x86-64 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.
Libpng
A collection of routines to create and manipulate PNG format graphic images. Designed as a replacement for GIF (and to a lesser extent TIFF) due to functional and patent problems, with more efficient compression (using Gzip-like DEFLATE), support for 24-bit color and alpha transparency.
Libwebp
Provides libwebp.so, a library for encoding and decoding WebP image files. It also contains the command line tools 'cwebp' and 'dwebp'. libwebp is Google's official encoder for WebP images. It can encode in either lossy or lossless mode. Lossy images are essentially a wrapper around a VP8 frame. Lossless images are a separate codec developed by Google. Currently, libwebp only supports YUV420 for lossy and RGB for lossless due to limitations of the format and libwebp. Alpha is supported for either mode. Because of API limitations, if RGB is passed in when encoding lossy or YUV is passed in for encoding lossless, the pixel format will automatically be converted using functions from libwebp. This is not ideal and is done only for convenience.
Mozjpeg
This library aims to speed up loading times of webpages by achieving a reduction in file size and therefore transmission time through improvement of coding efficiency while retaining image quality. To achieve this, it uses more processing power for the encoding (asymmetry) while retaining full compatibility with the JPEG standard and requiring no changes on the decoder side. The techniques MozJPEG uses to achieve high compression include optimising Huffman trees, using progressive coding to optimally split the spectrum of DCT coefficients into separate scans, and through the use of trellis quantisation. Additionally, the presets are aggressively tuned towards the minimisation of file sizes. MozJPEG is a fork of libjpeg-turbo. MozJPEG is compatible with the libjpeg API and ABI. It is intended to be a drop-in replacement for libjpeg. MozJPEG is a strict superset of libjpeg-turbo's functionality. All MozJPEG's improvements can be disabled at run time, and in that case it behaves exactly like libjpeg-turbo. Besides libjpeg-turbo, MozJPEG also builds upon jpegcrush, a Perl script by Loren Merritt. An internet application of this tool is available at https://mozjpeg.com/.

Features

  • Progressive encoding with "jpegrescan" optimization. It can be applied to any JPEG file (with jpegtran) to losslessly reduce file size.
  • Trellis quantization. When converting other formats to JPEG it maximizes quality/filesize ratio.
  • Comes with new quantization table presets, e.g. tuned for high-resolution displays.
  • Fully compatible with all web browsers.
  • Can be seamlessly integrated into any program that uses the industry-standard libjpeg API. There's no need to write any MozJPEG-specific integration code.
ObscuraCam
https://f-droid.org/en/packages/org.witness.sscphase1/ Obscuracam is a photo and video app for Android that keeps certain information private. Ever capture someone in a photo or video, then realize they may not want to be in it? Not comfortable posting a friend, family member or child’s face on the internet? Worried about the geolocation data in the picture giving away private hideaway? Tired of Facebook, Google and other sites “auto detecting” faces in your photos? Then this is for you, giving you the power to better protect the identity of those captures in your photos, before you post them online. Take a picture or load a photo or video from the Gallery, and ObscuraCam will automatically detect faces that you can pixelate, redact (blackout) or protect with funny nose and glasses. You can also invert pixelate, so that only the person you select is visible, and no one in the background can be recognized. This app will also remove all identifying data stored in photos including GPS location data and phone make & model. You can save the protected photo back to the Gallery or any other “Share” enabled app.
Orthanc
Orthanc aims at providing a simple, yet powerful standalone DICOM server. It is designed to improve the DICOM flows in hospitals and to support research about the automated analysis of medical images. Orthanc can turn any computer running Windows or GNU/Linux into a DICOM store (in other words, a mini-PACS system). Its architecture is lightweight and standalone, meaning that no complex database administration is required, nor the installation of third-party dependencies. What makes Orthanc unique is the fact that it provides a RESTful API. Thanks to this major feature, it is possible to drive Orthanc from any computer language. The DICOM tags of the stored medical images can be downloaded in the JSON file format. Furthermore, standard PNG images can be generated on-the-fly from the DICOM instances by Orthanc. Orthanc lets its users focus on the content of the DICOM files, hiding the complexity of the DICOM format and of the DICOM protocol.
Photocopy
Photocopy is an application to remove backgrounds from image scanned pages.
SimTaDyn
Manipulate a Geographic Information System like a spreadsheet.
Zbar
ZBar is a software suite for reading bar codes from various sources, such as video streams, image files and raw intensity sensors. It supports many popular symbologies (types of bar codes) including EAN-13/UPC-A, UPC-E, EAN-8, Code 128, Code 39, Interleaved 2 of 5 and QR Code. The flexible, layered implementation facilitates bar code scanning and decoding for any application: use it stand-alone with the included GUI and command line programs, easily integrate a bar code scanning widget into your Qt, GTK+ or PyGTK GUI application, leverage one of the script or programming interfaces (Python, Perl, C++) ...all the way down to a streamlined C library suitable for embedded use.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the page “GNU Free Documentation License”.

The copyright and license notices on this page only apply to the text on this page. Any software or copyright-licenses or other similar notices described in this text has its own copyright notice and license, which can usually be found in the distribution or license text itself.

Retrieved from "https://directory.fsf.org/wiki/Special:Ask"