Color depth is a computer graphics term describing the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel (bpp), particularly when specified along with the number of bits used. Higher color depth gives a broader range of distinct colors. Jump to: navigation, search Computer graphics (CG) is the field of visual computing, where one utilizes computers both to generate visual images synthetically and to integrate or alter visual and spatial information sampled from the real world. ... Jump to: navigation, search This article is about the unit of information. ... Jump to: navigation, search Color is an important part of the visual arts. ... Jump to: navigation, search A pixel (pix, 1932 abbreviation of pictures, coined by Variety headline writers + element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ... For the use of the term raster in radio regulation, see frequency raster. ... The framebuffer is a part of RAM in a computer allocated to hold the graphics information for one frame or picture. ...

Indexed color

A 2-bit indexed-color image. The color of each pixel is represented by a number; each number corresponds to a color in the palette.

With relatively low color depth, the stored value is typically an index into a color map or palette. The colors available in the palette itself may be fixed by the hardware or modifiable. Image File history File links Illustration of how an indexed palette works. ... An artists palette A palette is: A thin board that a painter holds and mixes colour pigments on. ...

• 1-bit color (2¹ = 2 colors) monochrome, often black and white
• 2-bit color (2² = 4 colors) CGA
• 4-bit color (2⁴ = 16 colors) as used by EGA and by the least common denominator VGA standard at higher resolution
• 8-bit color (2⁸ = 256 colors) VGA at low resolution, Super VGA

Jump to: navigation, search Something which is monochromatic has a single color. ... CGA may stand for: Certified General Accountant Color Graphics Adapter This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... EGA may stand for Enhanced Graphics Adapter Éléments de géométrie algébrique. ... Video Graphics Array (VGA) is a computer display standard first marketed in 1987 by IBM. VGA belongs to a family of earlier IBM video standards and largely remains backward compatible with them. ... Video Graphics Array (VGA) is a computer display standard first marketed in 1987 by IBM. VGA belongs to a family of earlier IBM video standards and largely remains backward compatible with them. ... Super Video Graphics Array, almost always abbreviated to Super VGA or just SVGA is a broad term that covers a wide range of computer display standards. ...

Direct color

As the number of bits increases, the number of possible colors becomes impractically large for a color map. In higher color depths, the color value typically directly encodes relative brightnesses of red, green, and blue to specify a color in the RGB color model. Jump to: navigation, search The RGB color model utilizes the additive model in which red, green, and blue light are combined in various ways to create other colors. ...

HiColor

HiColor or Highcolor is considered sufficient to provide life-like colors, and is encoded using either 15 or 16 bits: Highcolour (or Hicolour, Highcolor, Hicolor, Thousands on a Macintosh) graphics is a method of storing image information in a computers memory such that each pixel is represented by two bytes. ...

• 15-bit color uses 5 bits to represent red, 5 bits to represent blue, and 5 bits to represent green. 2⁵ = 32 levels of each of these three colour can therefore be combined to give a total of 32,768 mixed colours (32 x 32 x 32 = 32,768)

• 16-bit color uses 5 bits to represent red, 5 bits to represent blue, but (since the human eye is more sensitive to the color green) uses 6 bits to represent 64 levels of green. These can therefore be combined to give 65,536 mixed colours (32 x 32 x 64 = 65,536)

Truecolor

Truecolor can frequently mimic many colors found in the real world, producing 16.7 million distinct colors. This approaches the level at which the human eye can distinguish colors for most photographic images, though image manipulation, some black-and-white images (which are restricted to 256 levels with Truecolor) or "pure" generated images may reveal the limitations. Jump to: navigation, search Truecolor (also spelled Truecolour; called Millions on a Macintosh) graphics is a method of storing image information in a computers memory such that each pixel is represented by three or more bytes. ...

• 24-bit Truecolor uses 8 bits to represent red, 8 bits to represent blue, and 8 bits to represent green. 2⁸ = 256 levels of each of these three colour can therefore be combined to give a total of 16,777,216 mixed colours (256 x 256 x 256).

32-bit color

"32-bit color" is a misnomer when regarding display color depth. A common misconception is that 32-bit color produces 4,294,967,296 distinct colors.

In reality, 32-bit color actually refers to 24-bit color (Truecolor) with an additional 8 bits either as empty padding space or to represent an alpha channel. Considering red, green, and blue use the same amount of bits for their respective color (with the exception of 16-bit color), the total bits used will be a multiple of 3: like 15-bit color (5 bits each) and 24-bit color (8 bits each). The reason for using empty space is that all but the newest modern computers process data internally in units of 32 bits; as such, using this amount for each pixel can allow optimizations. In computer graphics, alpha compositing is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a process called compositing. ...

Beyond Truecolor

Professional-quality image manipulation and image generation software has started to employ 16 bits per color channel internally in recent years. While the 8 extra bits are not visible on-screen, they provide protection against accumulating rounding errors when multiple manipulations are performed on a picture, such as modifying image brightness and/or contrast. A round-off error is the difference between the calculated approximation of a number and its exact mathematical value. ...

Many high-quality scanners and a few high-priced graphics cards are able to recognize or show more than 8 bits per color channel as well. 10 bits per channel seem to be enough to reach the absolute limits of human vision under almost all circumstances. The term scanner has several meanings: In radio, a scanner is a device for searching for and receiving radio broadcasts. ... Image:Gef 7800. ...

For extended dynamic range imaging, including High Dynamic Range Imaging (HDRI), floating point numbers are used to describe numbers in excess of 'full' white and black. This allows an image to describe accurately the intensity of the sun and deep shadows in the same colour space. Various models are used to describe these ranges, many employing 32 bit accuracy per channel.

Selection of color depth

In graphics intensive applications such as computer games, a tradeoff of performance and quality can be achieved by raising or lowering the color depth of the display; graphics with lower color depths do not require as much frame buffer memory or display bandwidth, allowing them to be generated and displayed more quickly. Increasing color depth results in higher color quality at the expense of display speed and responsiveness. Jump to: navigation, search Bandwidth is a measure of frequency range. ...

See also

• RGB color model

Jump to: navigation, search The RGB color model utilizes the additive model in which red, green, and blue light are combined in various ways to create other colors. ...

External links

• Understanding Bit Depth: Basics and comparison
• Banding in low colour resolution workflows: Comparision and recomendations