Conceptually, an image in its simplest form (single-channel; for example, binary or mono-chrome, grayscale or black and white images) is a two-dimensional function f(x,y) that maps a coordinate-pair to an integer/real value, which is related to the intensity/color of the point. Each point is called a pixel or pel (picture element). An image can have multiple channels too (for example, colored RGB images, where a color can be represented using three channels—red, green, and blue). For a colored RGB image, each pixel at the (x,y) coordinate can be represented by a three-tuple (rx,y, gx,y, bx,y).
In order to be able to process it on a computer, an image f(x,y) needs to be digitalized both spatially ...
