This is a common graphics format used by some operating systems to store digital raster images. It can be likened to a map of bits, hence the name, as the image is made up of a number of individual dots (bits). Usually, the term bitmap refers to an uncompressed image stored as one bit per pixel.
Although the term bitmap stems from the more generic use in computer programming, for example, a map of bits (an array of binary digits), it has become more widely used to describe the image format. There is also the term pixmap
which is used to describe digital images that contain multiple bits per pixel.
Another term related to bitmap files is DIB
(Device Independent Bitmap) which, as its name suggests, is a device-independent file format which can be used to transfer and display bitmap images on various different devices using disparate operating systems.
The file extension normally used by the Windows®
and OS/2 operating systems for standard bitmap files is .bmp
. Other file formats for literal bitmaps include:
- InterLeaved Bitmap (ILBM)
- Portable Bitmap (PBM)
- Wireless Application Protocol Bitmap (WBMP)
- X Bitmap (XBM)
Bitmap files can get very large in filesize (i.e. kilobytes) and if storage space is a factor then it is best to convert the image into a more compressed format, such as JPEG.