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- ppppbbbbmmmm((((5555)))) XXXXEEEENNNNIIIIXXXX SSSSyyyysssstttteeeemmmm VVVV ((((22227777 SSSSeeeepppptttteeeemmmmbbbbeeeerrrr 1111999999991111)))) ppppbbbbmmmm((((5555))))
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- NNNNAAAAMMMMEEEE
- pbm - portable bitmap file format
-
- DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
- The portable bitmap format is a lowest common denominator
- monochrome file format. It was originally designed to make
- it reasonable to mail bitmaps between different types of
- machines using the typical stupid network mailers we have
- today. Now it serves as the common language of a large
- family of bitmap conversion filters. The definition is as
- follows:
-
- - A "magic number" for identifying the file type. A pbm
- file's magic number is the two characters "P1".
-
- - Whitespace (blanks, TABs, CRs, LFs).
-
- - A width, formatted as ASCII characters in decimal.
-
- - Whitespace.
-
- - A height, again in ASCII decimal.
-
- - Whitespace.
-
- - Width * height bits, each either '1' or '0', starting at
- the top-left corner of the bitmap, proceeding in normal
- English reading order.
-
- - The character '1' means black, '0' means white.
-
- - Whitespace in the bits section is ignored.
-
- - Characters from a "#" to the next end-of-line are ignored
- (comments).
-
- - No line should be longer than 70 characters.
-
- Here is an example of a small bitmap in this format:
- P1
- # feep.pbm
- 24 7
- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
- 0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0
- 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 1 0
- 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 1 0
- 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0
- 0 1 0 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0
- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-
- Programs that read this format should be as lenient as
- possible, accepting anything that looks remotely like a
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- Page 1 (printed 9/7/93)
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- ppppbbbbmmmm((((5555)))) XXXXEEEENNNNIIIIXXXX SSSSyyyysssstttteeeemmmm VVVV ((((22227777 SSSSeeeepppptttteeeemmmmbbbbeeeerrrr 1111999999991111)))) ppppbbbbmmmm((((5555))))
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- bitmap.
-
- There is also a variant on the format, available by setting
- the RAWBITS option at compile time. This variant is
- different in the following ways:
-
- - The "magic number" is "P4" instead of "P1".
-
- - The bits are stored eight per byte, high bit first low bit
- last.
-
- - No whitespace is allowed in the bits section, and only a
- single character of whitespace (typically a newline) is
- allowed after the height.
-
- - The files are eight times smaller and many times faster to
- read and write.
-
- SSSSEEEEEEEE AAAALLLLSSSSOOOO
- atktopbm(1), brushtopbm(1), cmuwmtopbm(1), g3topbm(1),
- gemtopbm(1), icontopbm(1), macptopbm(1), mgrtopbm(1),
- pi3topbm(1), xbmtopbm(1), ybmtopbm(1), pbmto10x(1),
- pnmtoascii(1), pbmtoatk(1), pbmtobbnbg(1), pbmtocmuwm(1),
- pbmtoepson(1), pbmtog3(1), pbmtogem(1), pbmtogo(1),
- pbmtoicon(1), pbmtolj(1), pbmtomacp(1), pbmtomgr(1),
- pbmtopi3(1), pbmtoplot(1), pbmtoptx(1), pbmtox10bm(1),
- pbmtoxbm(1), pbmtoybm(1), pbmtozinc(1), pbmlife(1),
- pbmmake(1), pbmmask(1), pbmreduce(1), pbmtext(1), pbmupc(1),
- pnm(5), pgm(5), ppm(5)
-
- AAAAUUUUTTTTHHHHOOOORRRR
- Copyright (C) 1989, 1991 by Jef Poskanzer.
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- Page 2 (printed 9/7/93)
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