bits per pixel

Also found in: Acronyms.

bits per pixel

(hardware, graphics)
(bpp) The number of bits of information stored per pixel of an image or displayed by a graphics adapter. The more bits there are, the more colours can be represented, but the more memory is required to store or display the image.

A colour can be described by the intensities of red, green and blue (RGB) components. Allowing 8 bits (1 byte) per component (24 bits per pixel) gives 256 levels for each component and over 16 million different colours - more than the human eye can distinguish. Microsoft Windows alls this truecolour. An image of 1024x768 with 24 bpp requires over 2 MB of memory.

"High colour" uses 16 bpp (or 15 bpp), 5 bits for blue, 5 bits for red and 6 bits for green. This reduced colour precision gives a slight loss of image quality at a 1/3 saving on memory.

Standard VGA uses a palette of 16 colours (4 bpp), each colour in the palette is 24 bit. Standard SVGA uses a palette of 256 colours (8 bpp).

Some graphics hardware and software support 32-bit colour depths, including an 8-bit "alpha channel" for transparency effects.
This article is provided by FOLDOC - Free Online Dictionary of Computing (
References in periodicals archive ?
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Wolf says the new 16/24 bits per pixel color support is important because with so many more colors supported - 16,000 to 32,000, as opposed to 256 previously - X terminals can share a much larger palette of colors and color flash, which occurs when two or more terminals are trying to share unlimited color palette, will not occur.
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