BMP is the standard file format for bit map data in Windows (There is also a slightly different BMP in the OS/2 format). It carries the extension, .bmp. BMP files can be viewed and edited with the Windows accessory program, MS Paint, and is compatible with various image processing software. It is a file format which conforms to the basic method for handling bit map data in Windows programs.

Most BMPs today are in a DIB (Device Independent Bitmap) file format and are capable of handling color modes such as RGB, indexed color, monochrome black and white, etc. and up to 32 bits of color (For example, in MS Paint, an image can be saved in 1-bit, 4-bit, 8-bit or 24-bit color). The image can also be compressed but this is not done very frequently. As indicated by the name “device independent bitmap”, this is a file format which was developed so that it can also be used in a simplified way in various environments and display devices, according to the number of colors available. For instance, in 24-bit color, the color information for a pixel can be stored as it is, but when there are fewer colors, the color palette can be used in much the same way as indexed color. BMP has a relatively simple structure for a bit map data file format and is a suitable example for learning about image file formats.

It is not used in desktop publishing (DTP) and other printing applications as it does not support CMYK color mode. BMP is used from time to time for images on a web page but this is not desirable. JPEG, PNG, GIF and other appropriate compressed file formats should be selected according to the type of image.