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Format

Windows Bitmap

Summary

Name
Windows Bitmap
Version
2.0
Identifiers
  • Apple Uniform Type Identifier: com.microsoft.bmp
  • PUID: fmt/115
  • MIME: image/bmp
Format type
Image (Raster)
Description
This is an outline record only, and requires further details, research or authentication to provide information that will enable users to further understand the format and to assess digital preservation risks associated with it if appropriate. If you are able to help by supplying any additional information concerning this entry, please return to the main PRONOM page and select ‘Add an Entry’. Windows bitmap 2.0 and OS/2 bitmap 1.0 are effectively the same format - the only difference is the data type of the width and height fields of the bitmap header – for Windows 2.0 bitmaps they are signed short integers, for OS/2 1.0 bitmaps they are unsigned shorts. For positive numbers the representation is the same. Consequently, the file formats cannot be distinguished with a file signature test. The PUID for OS/2 Bitmap 1.0 (x-fmt/25) has therefore been deprecated.
File extensions
bmp, dib
Source
Digital Preservation Department / The National Archives

Relationships

Equivalent to
Is previous version of
Is subsequent version of

Internal signatures

Windows Bitmap 2.0

Note
BITMAPFILEHEADER: File Type identifier “BM”, file size (4 butes); two short integer reserved fields with values zero, long integer offset to bitmap image data + BITMAPINFOHEADER: length of bitmap header, long integer 12; number of color planes, short integer, always 1; number of bits per pixel, short integer, 1, 4, 8 or 24.

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
None
Byte Sequence
424D{4}00000000{4}0C000000{4}0100(01|04|08|18)00
Endianness
None

Changelog

  • Updated in V51

    Release date
    15 July 2011

    Windows Bitmap 2.0: Existing signature refined by Georgia Tech Research Institute, USA.