In digital photography, computer-generated imagery, and colorimetry, a grayscale image is one in which the value of each pixel is a single sample representing only an amount of light; that is, it carries only intensity information. Grayscale images, a kind of black-and-white or gray monochrome, are composed exclusively of shades of gray. The contrast ranges from black at the weakest intensity to white at the strongest.
Examples of conversion from a full-color image to grayscale using Adobe Photoshop's Channel Mixer, compared to the original image and colorimetric conversion to grayscale
Digital photography uses cameras containing arrays of electronic photodetectors interfaced to an analog-to-digital converter (ADC) to produce images focused by a lens, as opposed to an exposure on photographic film. The digitized image is stored as a computer file ready for further digital processing, viewing, electronic publishing, or digital printing. It is a form of digital imaging based on gathering visible light.
The Mars Orbiter Camera selected by NASA in 1986 (costing US$44 million) contains a 32-bit radiation-hardened 10 MHz processor and 12 MB of DRAM, then considered state of the art.
Nikon D700 — a 12.1-megapixel full-frame DSLR
Canon PowerShot A95
First digital image ever created, by Russell Kirsch. It is an image of his son, Walden.