In digital imaging, a pixel, pel, dots, or picture element is a physical point in a raster image, or the smallest addressable element in an all points addressable display device ; so it is the smallest controllable element of a picture represented on the screen.
Each pixel is a sample of an original image ; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black.
In some contexts (such as descriptions of camera sensors), pixel refers to a single scalar element of a multi-component representation (more precisely called a photosite in the camera sensor context, although the neologism sensel is sometimes used to describe the elements of a digital camera 's sensor), while in yet other contexts it may refer to the set of component intensities for a spatial position. Drawing a distinction between pixels, photosites, and samples may reduce confusion when describing color systems that use chroma subsampling or cameras that use Bayer filter to produce color components via upsampling.
The word pixel is a portmanteau of pix (from "pictures", shortened to "pics") and el (for "element"); similar formations with 'el' include the words voxel and texel.
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