A Digital image, or digitized image, or digital picture function of an image, is an image represented numerically in digital form and is obtained by Partitioning the area of the image into a finite two-dimensional array of small, uniformly shaped, mutually exclusive regions, called Resolution cells or picture elements (pixels), and by assigning a representative grey shade to each such spatial region. A digital image may be abstractly thought of as a function whose Domain is the finite two-dimensional set of resolution cells and whose Range is the set of grey shades.