728 Windows Bitmap 2.0 BMP (2.0) Image (Raster) 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. Binary Little-endian (Intel) 1 Digital Preservation Department / The National Archives 11 Mar 2005 11 Jul 2011 com.microsoft.bmp Apple Uniform Type Identifier fmt/115 PUID image/bmp MIME bmp File extension dib File extension 117 Windows Bitmap 2.0 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. 1 Absolute from BOF 0 424D{4}00000000{4}0C000000{4}0100(01|04|08|18)00 Equivalent to 55 OS/2 Bitmap Is previous version of 729 Windows Bitmap Is previous version of 730 Windows Bitmap Is subsequent version of 727 Windows Bitmap