Bitmap

For other uses, see Bitmap (disambiguation).

In computing, a bitmap (also called raster) graphic is an image formed from rows of different colored pixels.[1] A GIF is an example of a graphics image file that uses a bitmap.[2]

As a noun, the term "bitmap" is very often used to refer to a particular bitmapping application: the pix-map, which refers to a map of pixels, where each pixel may store more than two colors, thus using more than one bit per pixel. In such a case, the domain in question is the array of pixels which constitute a digital graphic output device (a screen or monitor). In some contexts, the term bitmap implies one bit per pixel, whereas pixmap is used for images with multiple bits per pixel.[3][4]

A bitmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or memory.

Many graphical user interfaces use bitmaps in their built-in graphics subsystems.[5] For example, the Microsoft Windows and OS/2 platforms' GDI subsystem uses the Windows and OS/2 bitmap file format, usually named with the file extension .BMP (or .DIB for device-independent bitmap). Besides BMP, other file formats that store literal bitmaps include InterLeaved Bitmap (ILBM), Portable Bitmap (PBM), X Bitmap (XBM), and Wireless Application Protocol Bitmap (WBMP). Similarly, most other image file formats, such as JPEG, TIFF, PNG, and GIF, also store bitmap images (as opposed to vector graphics), but they are not usually referred to as bitmaps, since they use compressed formats internally.

  1. ^ "ARCHIVED: What are bitmap and vector graphics, and how are they different". University Information Technology Servivces. September 22, 2023. Archived from the original on April 21, 2024. Retrieved April 21, 2024.
  2. ^ Gregersen, Erik (January 26, 2022). "bitmap". Encyclopædia Britannica. Archived from the original on April 21, 2024. Retrieved April 21, 2024.
  3. ^ James D. Foley (1995). Computer Graphics: Principles and Practice. Addison-Wesley Professional. p. 13. ISBN 0-201-84840-6. The term bitmap, strictly speaking, applies only to 1-bit-per-pixel bilevel systems; for multiple-bit-per-pixel systems, we use the more general term pix-map (short for pixel map).
  4. ^ V.K. Pachghare (2005). Comprehensive Computer Graphics: Including C++. Laxmi Publications. p. 93. ISBN 81-7008-185-8.
  5. ^ Julian Smart; Stefan Csomor & Kevin Hock (2006). Cross-Platform GUI Programming with Wxwidgets. Prentice Hall. ISBN 0-13-147381-6.