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diff --git a/upstream/opensuse-leap-15-6/man1/pgmkernel.1 b/upstream/opensuse-leap-15-6/man1/pgmkernel.1 new file mode 100644 index 00000000..0605268c --- /dev/null +++ b/upstream/opensuse-leap-15-6/man1/pgmkernel.1 @@ -0,0 +1,124 @@ +\ +.\" 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 "Pgmkernel User Manual" 0 "19 December 2013" "netpbm documentation" +.UR #index +Table Contents +.UE +\& + +.SH NAME + +pgmkernel - generate a convolution kernel + +.UN synopsis +.SH SYNOPSIS +.PP +\fBpgmkernel\fP +[\fB-weight=\fP\fInumber\fP] +[\fB-maxval=\fP] {\fIsize\fP | \fIwidth\fP \fIheight\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 +\fBpgmkernel\fP generates a convolution kernel that you can use +with \fBpnmconvol\fP. The kernel is one where the weight of each location +is inversely proportional to its distance from the center of the kernel. +.PP +\fBpgmkernel\fP generates a PGM image of width and height \fIsize\fP +if you specify one argument, or width \fIwidth\fP and height \fIheight\fP +if you specify two arguments. +.PP +\fBpgmkernel\fP computes the convolution function K as follows. + +.RS +K(i,j) = 1 / ( 1 + w * sqrt(i^2 + j^2)) +.RE + +where \fIw\fP is a coefficient specified via the \fB-weight\fP +option. \fIi\fP and \fIj\fP are measured in pixels. K is zero +everywhere beyond the specified kernel width and height. +.PP +The sample values in the PGM output have this value scaled and biased using +the protocol \fBpnmconvol\fP specifies for representing the real numbers K +in PGM. + + +.UN options +.SH OPTIONS + + +.TP +\fB-weight=\fP\fInumber\fP +The distance from the center is weighted by this; a higher number means +the value falls off more quickly as you go away from the center. +.sp +This must be a positive real number. +.sp +The default is 6.0. + +.TP +\fB-maxval=\fP\fImaxval\fP +The maxval for the PGM kernel. +.sp +Default is 255. +.sp +This option was new in Netpbm 10.65 (December 2013). Before that, the +maxval is always 255. + + + + +.UN limitations +.SH LIMITATIONS +.PP +The computation time is proportional to \fIwidth\fP*\fIheight\fP. +This increases rapidly with the increase of the kernel size. A better +approach could be using a FFT in these cases. + +.UN history +.SH HISTORY +.PP +Before Netpbm 10.65 (December 2013), the output was always in +Plain (text) PGM format. (Now, like standard Netpbm programs, the default +is raw PGM and you can get Plain PGM with a \fB-plain\fP option). +.PP +Before Netpbm 10.65 (December 2013), this manual said negative values +for \fB-weight\fP were valid (as long as they were greater than -1.0). But +the program never worked with negative numbers and it isn't clear that the +result would be useful, so \fB-weight\fP is now required to be nonnegative +and the program fails gracefully if you specify a negative value. + +.UN seealso +.SH SEE ALSO +.BR "pnmconvol" (1)\c +\&, +.BR "pnmsmooth" (1)\c +\& +.BR "pamgauss" (1)\c +\& +.BR "pgm" (5)\c +\& + + +.UN author +.SH AUTHOR + +Alberto Accomazzi (\fIalberto@cfa.harvard.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/pgmkernel.html +.PP
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