APNG (Animated Portable Network Graphics) is an unofficial extension of the APNG (Portable Network Graphics) format. APNG patch provides APNG support to libpng.

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.

JBIG-KIT implements the JBIG1 data compression standard (ITU-T T.82 and ISO/IEC 11544:1993), designed for bi-level (one bit per pixel) images such as black-and-white scanned documents. It is widely used in fax products, printer firmware and drivers, document management systems, and imaging software.

This package provides a static C library of (de)compression functions and some simple command-line converters similar to those provided by netpbm.

Two JBIG1 variants are available. One (jbig.c) implements nearly all options of the standard but has to keep the full uncompressed image in memory. The other (jbig85.c) implements just the ITU-T T.85 profile, with memory management optimized for embedded and fax applications. It buffers only a few lines of the uncompressed image in memory and is able to stream images of initially unknown height.

Imlib2 is a library that does image file loading and saving as well as rendering, manipulation, arbitrary polygon support, etc.

It does ALL of these operations FAST. Imlib2 also tries to be highly intelligent about doing them, so writing naive programs can be done easily, without sacrificing speed.

This is a complete rewrite over the Imlib 1.x series. The architecture is more modular, simple, and flexible.

Nifti_clib is a set of I/O libraries for reading and writing files in the nifti-1, nifti-2, and (to some degree) cifti file formats. These are binary file formats for storing medical image data, e.g. MRI and fMRI brain images.

Gpick is an advanced color picker and palette editing tool.

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.

grim can create screenshots from a Wayland compositor.

Simple encoder and decoder for blurhashes. Contains a command line program as well as a shared library.

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.

IQA is a C library for objectively measuring image/video quality. It implements many popular algorithms, such as MS-SSIM, MS-SSIM*, SIMM, MSE, and PSNR. It is designed to be fast, accurate, and reliable. All code is Valgrind-clean and unit tested.

Nifti_clib is a set of I/O libraries for reading and writing files in the nifti-1, nifti-2, and (to some degree) cifti file formats. These are binary file formats for storing medical image data, e.g. MRI and fMRI brain images.

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.

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

MyPaint is a simple drawing and painting program that works well with Wacom-style graphics tablets.

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.

Steghide is a program to `hide' data in various kinds of image and audio files. This practice is known as steganography, but the method used by steghide is not very secure and should not be used where security is at stake. Even if a password is used, steghide offers little plausible deniability.

Nonetheless, neither color nor sample frequencies are changed, making the embedding resistant against first-order statistical tests not aimed specifically at this tool.

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.

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.

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.

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

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

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.

Gradia is a GTK 4 application for enhancing and preparing screenshots for blogs, social media, and documentation. It supports background customization, annotation tools (pen, arrow, text, highlight, stamp), padding, cropping, and various export formats.