libpng is the PNG image format reference implementation. Portable Network Graphics are the most widely used raster image format, patent-free, based on lossless data compression, support indexed/paletted, grayscale, and 24 or 32 bit truecolor images with transparency. It's also an highly extensible container format, with built-in color profiles and representation information, textual meta data, filters, progressive interlacing, and permits animations in the derived APNG or MNG formats.
Little CMS intends to be an OPEN SOURCE small-footprint color management engine, with special focus on accuracy and performance. It uses the International Color Consortium standard (ICC), which is the modern standard when regarding to color management. The ICC specification is widely used and is referred to in many International and other de-facto standards. It was approved as an International Standard, ISO 15076-1, in 2005.