Pngcrush optimizes PNG images. It can further losslessly compress them by as much as 40%.

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.

Leptonica is a C library and set of command-line tools for efficient image processing and image analysis operations. It supports rasterop, affine transformations, binary and grayscale morphology, rank order, and convolution, seedfill and connected components, image transformations combining changes in scale and pixel depth, and pixelwise masking, blending, enhancement, and arithmetic ops.

libheif is an ISO/IEC 23008-12:2017 HEIF and AVIF (AV1 Image File Format) file format decoder and encoder.

Libicns is a library for the manipulation of Mac OS IconFamily resource type files (ICNS). icns2png and png2icns are provided to convert between PNG and ICNS. icns2png will extract image files from ICNS files under names like "Foo_48x48x32.png" useful for installing for use with .desktop files. Additionally, icontainer2png is provided for extracting icontainer icon files.

PerceptualDiff visually compares two images to determine whether they look alike. It uses a computational model of the human visual system to detect similarities. This allows it too see beyond irrelevant differences in file encoding, image quality, and other small variations.

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.

OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG integrity checks and corrections.

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

swappy is a command-line utility to take and edit screenshots of Wayland desktops. Works great with grim, slurp and sway. But can easily work with other screen copy tools that can output a final PNG image to stdout.

pngcheck verifies the integrity of PNG, JNG and MNG files (by checking the internal 32-bit CRCs, a.k.a. checksums, and decompressing the image data); it can optionally dump almost all of the chunk-level information in the image in human-readable form. For example, it can be used to print the basic statistics about an image (dimensions, bit depth, etc.); to list the color and transparency info in its palette (assuming it has one); or to extract the embedded text annotations. This is a command-line program with batch capabilities (e.g. pngcheck *.png.)

Also includes pngsplit which can split a PNG, MNG or JNG file into individual, numbered chunks, and png-fix-IDAT-windowsize that allows resetting first IDAT's zlib window-size bytes and fix up CRC to match.

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.

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.

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.

The JasPer Project is an initiative to provide a reference implementation of the codec specified in the JPEG-2000 Part-1 standard (i.e., ISO/IEC 15444-1).

Gpick is an advanced color picker and palette editing tool.

libspng is a simple C library for loading Portable Network Graphics (PNGs), intended as an easy-to-use replacement for libpng.

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.

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.

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.

Libiptcdata is a C library for manipulating the International Press Telecommunications Council (IPTC) metadata stored within multimedia files such as images. This metadata can include captions and keywords, often used by popular photo management applications. The library provides routines for parsing, viewing, modifying, and saving this metadata.

grim can create screenshots from a Wayland compositor.

Mtpaint is a graphic editing program which uses the GTK+ toolkit. It can create and edit indexed palette or 24bit RGB images, offers basic painting and palette manipulation tools. It also handles JPEG, JPEG2000, GIF, TIFF, WEBP, BMP, PNG, XPM formats.

Libjpeg implements JPEG image encoding, decoding, and transcoding. JPEG is a standardized compression method for full-color and gray-scale images. It also includes programs that provide conversion between the JPEG format and image files in PBMPLUS PPM/PGM, GIF, BMP, and Targa file formats, as well as lossless JPEG manipulations such as rotation, scaling or cropping:

1. cjpeg

2. djpeg

3. jpegtran

4. rdjpgcom

5. wrjpgcom