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Diffstat (limited to 'upstream/debian-unstable/man1/ppmtopgm.1')
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diff --git a/upstream/debian-unstable/man1/ppmtopgm.1 b/upstream/debian-unstable/man1/ppmtopgm.1 new file mode 100644 index 00000000..d056c6e0 --- /dev/null +++ b/upstream/debian-unstable/man1/ppmtopgm.1 @@ -0,0 +1,96 @@ +\ +.\" This man page was generated by the Netpbm tool 'makeman' from HTML source. +.\" Do not hand-hack it! If you have bug fixes or improvements, please find +.\" the corresponding HTML page on the Netpbm website, generate a patch +.\" against that, and send it to the Netpbm maintainer. +.TH "Ppmtopgm User Manual" 1 "25 June 2017" "netpbm documentation" + +.SH NAME + +ppmtopgm - convert a PPM image to a PGM image + +.UN synopsis +.SH SYNOPSIS + +\fBppmtopgm\fP + +[\fIppmfile\fP] + +.UN description +.SH DESCRIPTION +.PP +This program is part of +.BR "Netpbm" (1)\c +\&. +.PP +\fBppmtopgm\fP reads a PPM as input and produces a PGM as output. +The output is a "black and white" rendering of the original +image, as in a black and white photograph. The quantization formula +\fBppmtopgm\fP uses is y = .299 r + .587 g + .114 b. +.PP +The dimensions and maxval of the output are the same as the input. +Note that with only one color plane, there are far fewer brightnesses +that can be represented with the same maxval than with three color +planes, so you may want to increase the maxval of the input with +\fBpamdepth\fP before giving it to \fBppmtopgm\fP to avoid loss of +information. For example, with a maxval of 1, there are 8 brightnesses that +are possible in a PPM (though some of them are barely distinguishable), but +only 2 brightness levels possible in a PGM. +.PP +Note that although there is a \fBpgmtoppm\fP program, it is not +necessary for simple conversions from pgm to ppm , because any ppm +program can read pgm (and pbm ) files automatically. \fBpgmtoppm\fP +is for colorizing a pgm file. Also, see \fBppmtorgb3\fP for a +different way of converting color to gray. And \fBppmdist\fP +generates a grayscale image from a color image, but in a way that +makes it easy to differentiate the original colors, not necessarily a +way that looks like a black and white photograph. + +.UN options +.SH OPTIONS +.PP +There are no command line options defined specifically +for \fBppmtopgm\fP, but it recognizes the options common to all +programs based on libnetpbm (See +.UR index.html#commonoptions + Common Options +.UE +\&.) + +.UN quote +.SH QUOTE + +.nf +Cold-hearted orb that rules the night +Removes the colors from our sight +Red is gray, and yellow white +But we decide which is right +And which is a quantization error. + +.fi + +.UN seealso +.SH SEE ALSO +.BR "pgmtoppm" (1)\c +\&, +.BR "ppmtorgb3" (1)\c +\&, +.BR "rgb3toppm" (1)\c +\&, +.BR "ppmdist" (1)\c +\&, +.BR "ppm" (1)\c +\&, +.BR "pgm" (1)\c +\& + +.UN author +.SH AUTHOR + +Copyright (C) 1989 by Jef Poskanzer. +.SH DOCUMENT SOURCE +This manual page was generated by the Netpbm tool 'makeman' from HTML +source. The master documentation is at +.IP +.B http://netpbm.sourceforge.net/doc/ppmtopgm.html +.PP
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