Alpha Channels
Chris Jackson · 2008
What Are Alpha Channels? An RGB image contains three color channels — red, green, and blue. When combined, these channels produce the full color image. The alpha channel is a fourth channel that contains an 8-bit grayscale image. This image determines the transparency of each pixel. Black pixels become transparent, and white pixels are opaque. Any value in between black and white has a certain degree of transparency. A 32-bit color image contains 24-bit color information with an 8-bit alpha channel.