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diff --git a/upstream/opensuse-tumbleweed/man1/pammasksharpen.1 b/upstream/opensuse-tumbleweed/man1/pammasksharpen.1 new file mode 100644 index 00000000..9ef92ab6 --- /dev/null +++ b/upstream/opensuse-tumbleweed/man1/pammasksharpen.1 @@ -0,0 +1,156 @@ +\ +.\" 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 "Pammasksharpen User Manual" 0 "14 June 2006" "netpbm documentation" + +.SH NAME +pammasksharpen - Sharpen an image via an unsharp mask + +.UN synopsis +.SH SYNOPSIS + +\fBpammasksharpen\fP +[\fB-sharpness=\fP\fIrealnum\fP] +[\fB-threshold=\fP\fIrealnum\fP] +\fImaskfile\fP [\fIinputfile\fP] +.PP +All options can be abbreviated to their shortest unique prefix. +You may use two hyphens instead of one. You may separate an option +name and its value with white space instead of an equals sign. + +.UN examples +.SH EXAMPLES + +.nf + pamgauss 5 5 -sigma=.7 -tupletype=GRAYSCALE | pamtopnm > gauss.pgm + pnmconvol -nooffset gauss.pgm myimage.ppm > blurred.ppm + pammasksharpen blurred.ppm myimage.ppm > sharpened.ppm + +.fi + + +.UN description +.SH DESCRIPTION +.PP +This program is part of +.BR "Netpbm" (1)\c +\&. +.PP +\fBpammasksharpen\fP reads a Netpbm image as input and produces a +sharpened version of it, in the same format, as output. It does this +via an unsharp mask, which you supply as another Netpbm image. +.PP +An unsharp mask is generally a blurred version of the original +image. The sharpening computation is this: Calculate the +"edgeness" of a sample in the input image as the signed +difference between the sample value and the corresponding sample in +the unsharp mask. This tells how different the pixel is from its +neighbors. Add a multiple of the edgeness to the original sample to +get the corresponding output sample. Clip as necessary. This causes +pixels that are brighter than their neighbors to get even brighter, +while pixels that are dimmer than their neighbors get even dimmer. +This makes edges -- places where pixel values change quickly in space +-- stand out more. +.PP +The unsharp mask must be the same dimensions and have the same maxval +as the input image. + +.SS The Unsharp Mask +.PP +You usually create the unsharp mask as a Gaussian blur of the +original image, which you can do using \fBpamgauss\fP and +\fBpnmconvol\fP as in the example above. The convolution kernel you +use with \fBpnmconvol\fP is normally a square with side length an odd +number of pixels. +.PP +When you create an unsharp mask like this, you will have to choose +the side length of the convolution kernel. That length implements the +parameter of unsharp mask sharpening usually known as +"radius." In particular, a radius of R pixels corresponds to a +convolution kernel 2R+1 pixels on a side. +.PP +Radius is a very important parameter; you can ruin an image with a +radius too large. You can safely use the highest radius with an +inanimate object, while a human face demands the least. Landscapes +fall in between. But it really depends on the size of the details. +Fine detail needs a smaller radius, or else you may obliterate tiny +detail of the same size as the Radius width. A large image often has +larger detail (more pixels involved), so can use a larger radius. +Radius and sharpness (see \fB-sharpness\fP option) interact: reducing +one allows you to increase the other. + +.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 +\&), \fBpammasksharpen\fP recognizes the following +command line options: + + + +.TP +\fB-sharpness=\fP\fIrealnum\fP +This specifies the magnitude of the sharpening. It is the multiple +of edgeness that gets added to each sample as described above. +.sp +\fIrealnum\fP is a nonnegative real decimal number. Zero means +no sharpening at all. +.sp +This parameter is known as "amount" in ImageMagick. +.sp +The default is 1.0. +.sp +This option was new in Netpbm 10.30 (October 2005). Before that, +the sharpness was always 1.0. + +.TP +\fB-threshold=\fP\fIrealnum\fP +This minimum amount of edgeness that will be considered edgeness +at all. i.e. if the magnitude of the edgeness is less than this, +\fBpammasksharpen\fP will treat the edgeness as zero. +.sp +A nonzero value may be necessary here to avoid speckling in smooth +areas. +.sp +This is a fraction of the maxval (so it is in the range [0, 1.0]). +.sp +The default is 0. +.sp +This option was new in Netpbm 10.34 (June 2006). + + + +.UN seealso +.SH SEE ALSO +.BR "pnmconvol" (1)\c +\&, +.BR "pamedge" (1)\c +\&, +.BR "pamsharpness" (1)\c +\&, +.BR "pamsharpmap" (1)\c +\&, +.BR "pamarith" (1)\c +\&, +.BR "pnm" (5)\c +\&, +.BR "pam" (5)\c +\& + + +.UN history +.SH HISTORY +.PP +\fBpammasksharpen\fP was new in Netpbm 10.23 (July 2004). +.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/pammasksharpen.html +.PP
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