Monochrome comes from the Greek μονόχρωμος (monochromos), meaning “of one color”, which is a combination of μόνος (monos), meaning “alone” or “solitary”, and χρώμα (chroma), meaning “color”. Monochromatic light is light of a single wavelength, though in practice it can refer to light of a narrow wavelength range. A monochromatic object or image is one whose range of colors consists of shades of a single color or hue; monochrome images in neutral colors are also known as grayscale or black-and-white.
In computing, monochrome has two meanings:
In film photography, monochrome is typically the use of black and white film. Originally, all photography was done in monochrome until the invention of color film plates in the early 20th century.
In digital photography, monochrome is the capture of only shades of black by the sensor, or by post-processing a color image to present only the perceived brightness by combining the values of multiple channels (usually red, blue, and green). The weighting of individual channels may be selected to achieve a desired artistic effect - if only the red channel is selected by the weighting then the effect will be similar to that of using a red filter on panchromatic film. If the red channel is eliminated and the green and blue combined then the effect will be similar to that of Orthochromatic film or the use of a cyan filter on panchromatic film. The selection of weighting thus allows a wide range of artistic expression in the final monochromatic image.
For production of an anaglyph image the original color stereogram source may first be reduced to monochrome in order to simplify the rendering of the image. This is sometimes required in cases where a color image would render in a confusing manner given the colors and patterns present in the source image and the selection filters used (typically red and its complement cyan),