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- ppm(5) Unix Programmer's Manual ppm(5)
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- NNNAAAMMMEEE
- ppm - portable pixmap file format
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- DDDEEESSSCCCRRRIIIPPPTTTIIIOOONNN
- The portable pixmap format is a lowest common denominator color image
- file format. The definition is as follows:
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- - A "magic number" for identifying the file type. A ppm file's magic
- number is the two characters "P3".
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- - Whitespace (blanks, TABs, CRs, LFs).
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- - A width, formatted as ASCII characters in decimal.
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- - Whitespace.
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- - A height, again in ASCII decimal.
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- - Whitespace.
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- - The maximum color-component value, again in ASCII decimal.
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- - Whitespace.
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- - Width * height pixels, each three ASCII decimal values between 0 and
- the specified maximum value, starting at the top-left corner of the
- pixmap, proceding in normal English reading order. The three values
- for each pixel represent red, green, and blue, respectively; a value of
- 0 means that color is off, and the maximum value means that color is
- maxxed out.
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- - Characters from a "#" to the next end-of-line are ignored (comments).
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- - No line should be longer than 70 characters.
-
- Here is an example of a small pixmap in this format:
- P3
- # feep.ppm
- 4 4
- 15
- 0 0 0 0 0 0 0 0 0 15 0 15
- 0 0 0 0 15 7 0 0 0 0 0 0
- 0 0 0 0 0 0 0 15 7 0 0 0
- 15 0 15 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 pixmap.
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- 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:
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- - The "magic number" is "P6" instead of "P3".
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- - The pixel values are stored as plain bytes, instead of ASCII decimal.
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- 15 September 1990 1
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- ppm(5) Unix Programmer's Manual ppm(5)
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- - Whitespace is not allowed in the pixels area, and only a single
- character of whitespace (typically a newline) is allowed after the
- maxval.
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- - The files are smaller and many times faster to read and write.
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- Note that this raw format can only be used for maxvals less than or equal
- to 255. If you use the _p_p_m library and try to write a file with a larger
- maxval, it will automatically fall back on the slower but more general
- plain format.
-
- SSSEEEEEE AAALLLSSSOOO
- giftoppm(1), gouldtoppm(1), ilbmtoppm(1), imgtoppm(1), mtvtoppm(1),
- pcxtoppm(1), pgmtoppm(1), pi1toppm(1), picttoppm(1), qrttoppm(1),
- rawtoppm(1), rgb3toppm(1), spctoppm(1), sputoppm(1), tgatoppm(1),
- ximtoppm(1), xpmtoppm(1), ppmtogif(1), ppmtoicr(1), ppmtoilbm(1),
- ppmtopcx(1), ppmtopgm(1), ppmtopi1(1), ppmtopict(1), ppmtops(1),
- ppmtopuzz(1), ppmtorgb3(1), ppmtouil(1), ppmtoxpm(1), ppmhist(1),
- ppmmake(1), ppmpat(1), ppmquant(1), ppmquantall(1), ppmrelief(1), pnm(5),
- pgm(5), pbm(5)
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- AAAUUUTTTHHHOOORRR
- Copyright (C) 1989, 1991 by Jef Poskanzer.
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- 15 September 1990 2
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