Image editing encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. Before digital scanners and cameras became mainstream, traditional analog image editing was known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any traditional art medium. However, since the advent of digital images, analog image editing has become largely obsolete. Graphic software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, and 3d modelers, are the primary tools with which a user may manipulate, enhance, and transform images. Many image editing programs are also used to render or create computer art from scratch.

Basics of image editing:
Raster images are stored in a computer in the form of a grid of picture elements, or pixels. These pixels contain the image's color and brightness information. Image editors can change the pixels to enhance the image in many ways. The pixels can be changed as a group, or individually, by the sophisticated algorithms within the image editors. The domain of this article primarily refers to bitmap graphics editors, which are often used to alter photographs and other raster graphics. However, vector graphics software, such as Adobe Illustrator or Inkscape, are used to create and modify vector images, which are stored as descriptions of lines, Bézier splines, and text instead of pixels. It is easier to rasterize a vector image than to vectorize a raster image- how to go about vectorizing a raster image is the focus of much research in the field of computer vision. People like vector images because they are easy to modify, containing descriptions of the shapes in them for easy rearrangement, as well as scalable, being rasterizable at any resolution- to rasterize a vector image is simply to render it, while scaling a raster image up involves guessing at data that isn't there (see aliasing and other articles on information theory for more), and even scaling a raster image down involves guessing unless the scaling factor is an integer.