The bit depth or color depth of a digital image is the number of binary bits (bits) used to encode the color of a single pixel.
It is necessary to distinguish between the terms bit per channel (bpc – bits per channel) and bit per pixel (bpp – bits per pixel). The bit depth for each of the individual color channels is measured in bits per channel, while the sum of the bits of all channels is expressed in bits per pixel. For example, an image in the Truecolor palette has a resolution of 8 bits per channel, which is equivalent to 24 bits per pixel, because the color of each pixel is described by three color channels: red, green and blue (RGB model). Continue reading