| bit map or bit·map (bĭt'māp') n. Computer Science A set of bits that represents a graphic image, with each bit or group of bits corresponding to a pixel in the image. |
| Main Entry: | bitmap |
| Part of Speech: | n |
| Definition: | See raster image |
bitmap  (bĭt'māp') Pronunciation Key
Computer Science A set of bits that represents a graphic image. Each bit or group of bits corresponds to a pixel in the image. Optical scanners and fax machines convert text or pictures into bitmaps. |
bitmap graphics, file format
A data file or structure which corresponds bit for bit with an image displayed on a screen, probably in the same format as it would be stored in the display's video memory or maybe as a device independent bitmap. A bitmap is characterised by the width and height of the image in pixels and the number of bits per pixel which determines the number of shades of grey or colours it can represent. A bitmap representing a coloured image (a "pixmap") will usually have pixels with between one and eight bits for each of the red, green, and blue components, though other colour encodings are also used. The green component sometimes has more bits that the other two to cater for the human eye's greater discrimination in this component.
See also vector graphics, image formats.
(1996-09-21)