PBMB Files Portable Bit Map (binary) (original) (raw)
PBMB is a data directory which contains examples of the binary version of the portable bitmap PBM format, a lowest common denominator monochrome file format. It was originally designed to make it reasonable to mail bitmaps between different types of machines. Now it serves as the common language of a large family of bitmap conversion filters. The definition is as follows:
- the typical file extension is ".pbm", but an extension of ".pnm" is also occasionally used.
- A "magic number" for identifying the file type. A binary PBMB file's magic number is the two characters "P4".
- Whitespace (blanks, TABs, CRs, LFs).
- A width, formatted as ASCII characters in decimal.
- Whitespace.
- A height, again in ASCII decimal.
- Whitespace. (It may be the case that this is required to be a single character of whitespace, usually a new line.)
- Width * height bits, stored 8 bits per byte, high bit first and low bit last, starting at the top-left corner of the bitmap, proceeding in normal English reading order. The bit '1' means black, '0' means white.
Binary PBM File Characteristics:
- binary
- black and white
- 2D
- No compression
- 1 image
Licensing:
The computer code and data files described and made available on this web page are distributed underthe GNU LGPL license.
Related Data and Programs:
PBMA, a data directory which contains examples of ASCII Portable Bit Map files.
PGMB, a data directory which contains examples of binary Portable Gray Map files.
PPMB, a data directory which contains examples of binary Portable Pixel Map files.
Reference:
Sample Files:
- <apollonian%5Fgasket.pbm>, a 600 wide by 600 high image of an Apollonian gasket.
- <apollonian%5Fgasket.png>, a PNG image.
- <circle.pbm>, a circle, drawn on a 200 by 200 grid;
- <circle.png>, a PNG version.
- <dla.pbm>, an 800 by 800 image of a structure created by diffusion-limited aggregation.
- <dla.png>, a PNG version.
- <feep.pbm>, the example described above, on a 24 by 7 grid;
- <feep.png>, a PNG version.
- <fool.pbm>, a screenshot from "The Fool's Errand".
- <fool.png>, a PNG version.
- <gerrymander.pbm>, an image of the "Gerry-mander", on a 303 by 325 grid;
- <gerrymander.png>, a PNG version.
- <letter%5Fa.pbm>, a capital A, using a 25 by 25 grid.
- <letter%5Fa.png>, a PNG version.
- <math%5Femporium.pbm>, a blueprint of the Math Emporium at Virginia Tech, on a 1376 by 1096 grid.
- <math%5Femporium.png>, a PNG version.
- pbmlib.pbm, a file created by PBMLIB.
- pbmlib.png, a PNG version.
- <scs.pbm>, the letters "SCS", on a grid 136 wide and 82 high.
- <scs.png>, a PNG version.
- <seahorse.pbm>, a silhouette of a sea horse, on a grid 2225 wide and 3601 high.
- <seahorse.png>, a PNG version.
- <sierpinski.pbm>, an image of the Sierpinksi fractal triangle, on a grid 966 wide and 860 high.
- <sierpinski.png>, a PNG version.
- <washington.pbm>, a silhouette of George Washington, on a grid 305 wide and 400 high.
- <washington.png>, a PNG version.
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Last revised on 14 July 2011.