Windows Bitmap (BMP)


General Description

The bitmap format was introduced in the early 1.1 version of OS/2. Later, Microsoft Corp. enhanced the format and included it in its best selling operating environment: Microsoft Windows 3.0. In OS/2 2.0 IBM further extended the format by adding some fields and by defining a structure for storing multiple bitmaps in the same file (this type of file is often referred to as a bitmap array). Although we have put much effort into making PMView save files with all the possible bitmap compression schemes, we discourage you from using then since many applications cannot deal with compressed Windows bitmaps.


The extension RLE is sometimes used for run length encoded bitmap files under Windows. Another common extension under Windows is DIB. BMP is the default extension for bitmap files.


Supporting Platforms and Applications

Intel machines running Microsoft Windows, MS-DOS, Windows NT.


PMView Support

PMView will read all types of OS/2 and Windows bitmaps.


The following bitmap types, bitcounts and compressions are supported:


IBM OS/2 1.x bitmaps   1, 2, 4, 8, 24

IBM OS/2 1.x bitmap arrays  1, 2, 4, 8, 24

IBM OS/2 2.x bitmaps   1, 2, 4, 8, 24 HUFFMAN_1D, RLE_4, RLE_8, RLE_24

IBM OS/2 2.x bitmap arrays  1, 2, 4, 8, 24 HUFFMAN_1D, RLE_4, RLE_8, RLE_24

Windows 3.x bitmaps   1, 2, 4, 8, 24 RLE_4, RLE_8

HUFFMAN_1D: Modified Huffman 1D encoding. Applicable only to black & white images.

RLE_4: Run length encoding. Applicable to images with 4 bits per pixel (16 colors or fewer)

RLE_8: Run length encoding, 8 bits per pixel (256 colors or fewer)

RLE_24: Run length encoding, 24 bits per pixel (deep color images)