Bitmap formats (also called raster or pixel maps) use a grid of pixel points to represent an image. The value of each pixel, representing its degree of darkness or color, is recorded individually. Bitmap formats work well for images with complex variations in colors, shades, or shapes. Continuous tone photographs are an example of a graphic that benefits from being stored in a bitmap format.

Bitmap image files require a relatively large amount of storage space and more memory to process and display. The ability to store images in compressed form is important for bitmap formats. To handle this problem, graphic software uses a variety of compression and encoding methods. This variety of methods can cause incompatibility problems among software programs trying to use the same graphics files.