Image file format in the context of "GIMP"

Digital imaging or digital image acquisition is the creation of a digital representation of the visual characteristics of an object, such as a physical scene or the interior structure of an object. The term is often assumed to imply or include the processing, compression, storage, printing and display of such images. A key advantage of a digital image, versus an analog image such as a film photograph, is the ability to digitally propagate copies of the original subject indefinitely without any loss of image quality.

Digital imaging can be classified by the type of electromagnetic radiation or other waves whose variable attenuation, as they pass through or reflect off objects, conveys the information that constitutes the image. In all classes of digital imaging, the information is converted by image sensors into digital signals that are processed by a computer and made output as a visible-light image. For example, the medium of visible light allows digital photography (including digital videography) with various kinds of digital cameras (including digital video cameras). X-rays allow digital X-ray imaging (digital radiography, fluoroscopy, and CT), and gamma rays allow digital gamma ray imaging (digital scintigraphy, SPECT, and PET). Sound allows ultrasonography (such as medical ultrasonography) and sonar, and radio waves allow radar. Digital imaging lends itself well to image analysis by software, as well as to image editing (including image manipulation).

In computer graphics and digital photography, a raster graphic, raster image, or simply raster is a digital image made up of a rectangular grid of tiny colored (usually square) so-called pixels. Unlike vector graphics which use mathematical formulas to describe shapes and lines, raster images store the exact color of each pixel, making them ideal for photographs and images with complex colors and details. Raster images are characterized by their dimensions (width and height in pixels) and color depth (the number of bits per pixel). They can be displayed on computer displays, printed on paper, or viewed on other media, and are stored in various image file formats.

The printing and prepress industries know raster graphics as contones (from "continuous tones"). In contrast, line art is usually implemented as vector graphics in digital systems.

Transparency in computer graphics is possible in a number of file formats. The term "transparency" is used in various ways by different people, but at its simplest there is "full transparency" i.e. something that is completely invisible. Only part of a graphic should be fully transparent, or there would be nothing to see. More complex is "partial transparency" or "translucency" where the effect is achieved that a graphic is partially transparent in the same way as colored glass. Since ultimately a printed page or computer or television screen can only be one color at a point, partial transparency is always simulated at some level by mixing colors. There are many different ways to mix colors, so in some cases transparency is ambiguous.

In addition, transparency is often an "extra" for a graphics format, and some graphics programs will ignore the transparency.

The JPEG File Interchange Format (JFIF) is an image file format standard published as ITU-T Recommendation T.871 and ISO/IEC 10918-5. It defines supplementary specifications for the container format that contains the image data encoded with the JPEG algorithm. The base specifications for a JPEG container format are defined in Annex B of the JPEG standard, known as JPEG Interchange Format (JIF). JFIF builds over JIF to solve some of JIF's limitations, including unnecessary complexity, component sample registration, resolution, aspect ratio, and color space. Because JFIF is not the original JPG standard, one might expect another MIME type. However, it is still registered as "image/jpeg" (indicating its primary data format rather than the amended information).

JFIF is mutually incompatible with the newer Exchangeable image file format (Exif).

Interchange File Format (IFF) is a generic digital container file format originally introduced by Electronic Arts (in cooperation with Commodore) in 1985 to facilitate transfer of data between software produced by different companies.

IFF files do not have any standard filename extension. On many systems that generate IFF files, file extensions are not important because the operating system stores file format metadata separately from the file name. The .iff filename extension is commonly used for the ILBM image file format, which uses the IFF container format.

WebP (/ˈwɛpi/ WEP-ee) is a raster graphics file format developed by Google and intended as a replacement for the JPEG, PNG, and GIF file formats on the web. It supports image compression (both lossy and lossless), as well as animation and alpha compositing. The sister project for video is called WebM.

Google announced the WebP format in September 2010; the company released the first stable version of its supporting library in April 2018. WebP has seen widespread adoption across the Internet in order to reduce image size, with all major browsers currently supporting the format.

The JPEG XL Image Coding System (JPEG XL, sometimes shortened to JXL) is an image format that supports both lossy and lossless compression. It was developed by the Joint Photographic Experts Group (JPEG), Google and Cloudinary. It is a free and open standard defined by ISO/IEC 18181. The standard consists of four parts that cover the Core coding system, File format, Conformance testing, and Reference software, respectively.

JPEG XL features a lossy compression mode called VarDCT built on block-based transform coding, which is similar to — but significantly improves and expands upon — the compression method of JPEG, and a modular mode that allows different features of the format to be combined in a "modular" way. Modular mode can be used either for lossless image compression, similar to PNG, or as a means to achieve lossy compression in a different way from VarDCT.

Tag Image File Format or Tagged Image File Format, commonly known by the abbreviations TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers.TIFF is widely supported by scanning, faxing, word processing, optical character recognition, image manipulation, desktop publishing, and page-layout applications.

The format was created by Stephen Carlsen, an engineer at Aldus Corporation, for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an Adobe Systems copyright after the latter acquired Aldus in 1994. Several Aldus or Adobe technical notes have been published with minor extensions to the format, and several specifications have been based on TIFF 6.0, including TIFF/EP (ISO 12234-2), TIFF/IT (ISO 12639), TIFF-F (RFC 2306) and TIFF-FX (RFC 3949).