The alpha channel is one of four channels within a 32-bit graphics system. It manages how a pixel's color should be combined with another pixel's color when one pixel is on top of the other. The alpha channel is a type of mask that is used to control the transparency of a graphic object.
Alpha channels are used for compositing algebra, which is a way to mesh objects or overlay them to form new objects. This is used in animation and other graphic arts. Depending on how much background is to be shown, different objects can contain different amounts of transparency. For frame movement in animation, a rectangular object can be made to be transparent so that the background is visible through it.When the alpha channel is used in an image, the color may be multiplied by the alpha value in a technique referred to as premultiplied alpha. Premultiplied alpha prevents an application from having to perform additional multiplications when compositing is being done. Single alpha channels are not suitable for some applications. Several alpha channels can be added together for spectral color filtration applications.
Get Techopedia delivered to your inbox!