n. An element in an array that forms an image. A unit of measure used to describe the size or resolution of an image.


A pixel1 contains information about the brightness and, for color images, the hue of the element. A pixel may be represented by a single bit, restricting the image to bitonal values. In monochromatic images, a pixel is at least a byte, capable of representing 256 shades. For color images, a one-byte pixel can represent only 256 colors; a three-byte pixel can represent more than 16 million colors. The height and width of an image are often measured in terms of pixels, and the resolution may be measured in terms of pixels per inch or centimeter.