libungif is the old GIF decompression library by the GIFLIB project.

A pretty small png library. Currently all documentation resides in pnglite.h.

libyuv is an open source project that includes YUV scaling and conversion functionality. It can:

• Scale YUV to prepare content for compression, with point, bilinear or box filter.

• Convert to YUV from webcam formats for compression.

• Convert to RGB formats for rendering/effects.

• Rotate by 90/180/270 degrees to adjust for mobile devices in portrait mode.

Didder is a command-line image dithering tool. It can also be used for pipeline scripting. It is backed by dithering library. It provides various dithering algorithms and you can provide your own by specifying a matrix in json format

Picket is a screen color picker that includes a magnifier and supports custom formats for representing color values..

libimagequant is a small, portable C library for high-quality conversion of RGBA images to 8-bit indexed-color (palette) images. This library can significantly reduces file sizes and powers pngquant and other PNG optimizers.

Jp2a is a small utility that converts JPEG images to ASCII.

Exiv2 is a C++ library and a command line utility to manage image metadata. It provides fast and easy read and write access to the Exif, IPTC and XMP metadata of images in various formats.

VIGRA stands for Vision with Generic Algorithms. It is an image processing and analysis library that puts its main emphasis on customizable algorithms and data structures. It is particularly strong for multi-dimensional image processing.

Libmng is the MNG (Multiple-image Network Graphics) reference library.

imgp is a command line image resizer and rotator for JPEG and PNG images. It can resize (or thumbnail) and rotate thousands of images in a go while saving significantly on storage.

This package may optionally be built with python-pillow-simd in place of python-pillow for SIMD parallelism.

libjpeg-turbo is a JPEG image codec that accelerates baseline JPEG compression and decompression using SIMD instructions: MMX on x86, SSE2 on x86-64, NEON on ARM, and AltiVec on PowerPC processors. Even on other systems, its highly-optimized Huffman coding routines allow it to outperform libjpeg by a significant amount. libjpeg-turbo implements both the traditional libjpeg API and the less powerful but more straightforward TurboJPEG API, and provides a full-featured Java interface. It supports color space extensions that allow it to compress from and decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.).

OpenJPEG is an implementation of JPEG 2000 codec written in C language. It has been developed in order to promote the use of JPEG 2000, a still-image compression standard from the Joint Photographic Experts Group (JPEG). Since April 2015, it is officially recognized by ISO/IEC and ITU-T as a JPEG 2000 Reference Software.

Giblib is a simple library which wraps imlib2's context API, avoiding all the context_get/set calls, adds fontstyles to the truetype renderer and supplies a generic doubly-linked list and some string functions.

This package provides a C interface to the VIGRA C++ computer vision library. It is designed primarily to ease the implementation of higher-level language bindings to VIGRA.

Exiv2 is a C++ library and a command line utility to manage image metadata. It provides fast and easy read and write access to the Exif, IPTC and XMP metadata of images in various formats.

jpegoptim provides lossless optimization (based on optimizing the Huffman tables) and "lossy" optimization based on setting maximum quality factor.

libjpeg-turbo is a JPEG image codec that accelerates baseline JPEG compression and decompression using SIMD instructions: MMX on x86, SSE2 on x86-64, NEON on ARM, and AltiVec on PowerPC processors. Even on other systems, its highly-optimized Huffman coding routines allow it to outperform libjpeg by a significant amount. libjpeg-turbo implements both the traditional libjpeg API and the less powerful but more straightforward TurboJPEG API, and provides a full-featured Java interface. It supports color space extensions that allow it to compress from and decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.).

GGG (Guile Glyph Generator) is a command-line utility that allows you to generate pretty images/badges which can be used for your projects, announcing tech used, sponsoring and appreciating other projects, distinguishing versions of things supported, etc.

GGG is highly configurable, reads Scheme files where you define your tasks, and supports badges between one and three parts. It leverages SVG generation from Lisp and S-expressions, building pixel perfect badges.

WebP is a new image format that provides lossless and lossy compression for images. WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25-34% smaller in size compared to JPEG images at equivalent SSIM index. WebP supports lossless transparency (also known as alpha channel) with just 22% additional bytes. Transparency is also supported with lossy compression and typically provides 3x smaller file sizes compared to PNG when lossy compression is acceptable for the red/green/blue color channels.

Phockup is a media sorting tool that uses creation date and time information in photos and videos to organize them into folders by year, month and day. All files which are not images or videos or those which do not have creation date information will be placed in a folder called unknown.

LibSIXEL is a an encoder/decoder implementation for DEC SIXEL graphics, and some converter programs. SIXEL is one of image formats for printer and terminal imaging introduced by DEC. Its data scheme is represented as a terminal-friendly escape sequence. So if you want to view a SIXEL image file, all you have to do is cat it to your terminal.

Gpick is an advanced color picker and palette editing tool.

Libavif is a C implementation of AVIF. It can encode and decode all YUV formats and bit depths supported by AOM, including with alpha.