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diff --git a/upstream/mageia-cauldron/man1/pgmmedian.1 b/upstream/mageia-cauldron/man1/pgmmedian.1 new file mode 100644 index 00000000..a585420f --- /dev/null +++ b/upstream/mageia-cauldron/man1/pgmmedian.1 @@ -0,0 +1,161 @@ +\ +.\" 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 "Pgmmedian User Manual" 0 "20 January 2022" "netpbm documentation" + +.SH NAME +pgmmedian - apply a median filter to a PGM file + +.UN synopsis +.SH SYNOPSIS + +\fBpgmmedian\fP + +[\fB-width=\fP\fIn\fP] + +[\fB-height=\fP\fIn\fP] + +[\fB-type=\fP\fImedian_type\fP] + +[\fB-cutoff=\fP\fIint\fP] + +[\fIpnmfile\fP] +.PP +Minimum unique abbreviation of option is acceptable. You may use double +hyphens instead of single hyphen to denote options. You may use white +space in place of the equals sign to separate an option name from its value. + + +.UN description +.SH DESCRIPTION +.PP +This program is part of +.BR "Netpbm" (1)\c +\&. +.PP +\fBpgmmedian\fP applies a median filter to a PGM image, using either +the histogram sort or select kth value method to determine the median. +.PP +A median filter is a convolution filter in which the value of a pixel in +the output is the median of a certain set of pixels in the neighborhood of the +corresponding input pixel. The effect is to eliminate locally extreme values. +Such pixels typically show up as speckles. +.PP +Pixels at the edges of the image, pixels where the convolution kernel would +go off the edge of the image, are just copied. For example, if \fB-height\fP +is 9, the first 4 and last 4 rows of the input image are just copied to the +output. + +.PP +See the \fB-type\fP and \fB-cutoff\fP options for information on +how \fBpgmmedian\fP chooses between the two methods. + + +.UN options +.SH OPTIONS +.PP +In addition to the options common to all programs based on libnetpbm +(most notably \fB-quiet\fP, see +.UR index.html#commonoptions + Common Options +.UE +\&), \fBpgmmedian\fP recognizes the following +command line options: + + +.TP +\fB-cutoff\fP \fIint\fP +This option provides the cutoff value that \fBpgmmedian\fP uses +to decide between using the histogram sort or select kth value method +to find the median. + +If (\fImaxval\fP / ((\fIwidth\fP * \fIheight\fP) - 1)), where +\fImaxval\fP is the maxval of the image and \fIwidth\fP and +\fIheight\fP are the dimensions of the mask, is less than the cutoff +value, \fBpgmmedian\fP uses histogram sort. Otherwise, it uses kth +value. +.sp +This option has no effect if you specify \fB-type\fP. +.sp +The default is 250 + +.TP +\fB-width=\fP\fIn\fP +Width of the median mask to apply. +.sp +Maximum allowed is the width of the input image. +.sp +Default is 3. + +.TP +\fB-height=\fP\fIn\fP +Height of the median mask to apply. +.sp +Maximum allowed is the height of the input image. +.sp +Default is 3. + +.TP +\fB-type\fP \fImedian_type\fP +This option selects which method to use to find median regardless +of cutoff value. Choices are \fBhistogram_sort\fP and \fBselect\fP. +.sp +By default, \fBpgmmedian\fP decides which method to use as described +under the \fB-cutoff\fP option. + + + +.UN references +.SH REFERENCES + + + +.IP \(bu +"Collected Algorithms from ACM" Volume II, Algorithm 489 +by Robert W. Floyd + +.IP \(bu +"A Fast Two-Dimensional Median Filtering Algorithm" in +"IEEE Transactions on Acoustics, Speech, and Signal +Processing" Vol. ASSP-27, No. 1, February 1979 + +.IP \(bu +"Digital Image Processing Algorithms" by Ioannis +Pitas, Prentice Hall, 1993 ISBN 0-13-145814-0 + + + + +.UN seealso +.SH SEE ALSO +.BR "pgmnoise" (1)\c +\&, +.BR "pamaddnoise" (1)\c +\&, +.BR "pnmconvol" (1)\c +\&, +.BR "pgmmorphconv" (1)\c +\&, +.BR "pgm" (1)\c +\& + +.UN history +.SH HISTORY +.PP +\fBpgmmedian\fP was added to Netpbm in Version 10.29 (August 2005). +It had been distributed by Mike Burns via his own web site before that +(and continued to be so). + + +.UN author +.SH AUTHOR + +Copyright (C) 1996 by Mike Burns <\fIburns@cac.psu.edu\fP> +.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/pgmmedian.html +.PP
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