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diff --git a/upstream/opensuse-tumbleweed/man1/pnmrotate.1 b/upstream/opensuse-tumbleweed/man1/pnmrotate.1 new file mode 100644 index 00000000..f8bf820d --- /dev/null +++ b/upstream/opensuse-tumbleweed/man1/pnmrotate.1 @@ -0,0 +1,148 @@ +\ +.\" 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 "Pnmrotate User Manual" 0 "30 August 2002" "netpbm documentation" + +.SH NAME +pnmrotate - rotate a PNM image by some angle + +.UN synopsis +.SH SYNOPSIS + +\fBpnmrotate\fP +[\fB-noantialias\fP] [\fB-background=\fP\fIcolor\fP] \fIangle\fP +[\fIpnmfile\fP] + +.UN description +.SH DESCRIPTION +.PP +This program is part of +.BR "Netpbm" (1)\c +\&. + +\fBpnmrotate\fP reads a PNM image as input. It rotates it by the +specified angle and produces the same kind of PNM image as output. +.PP +The input is the file named by \fIpnmfile\fP or Standard Input if you +don't specify \fIpnmfile\fP. The output goes to Standard Output. +.PP +The resulting image is a rectangle that contains the (rectangular) +input image within it, rotated with respect to its bottom edge. The +containing rectangle is as small as possible to contain the rotated +image. The background of the containing image is a single color that +\fBpnmrotate\fP determines to be the background color of the original +image, or that you specify explicitly. +.PP +\fIangle\fP is in decimal degrees (floating point), measured +counter-clockwise. It can be negative, but it should be between -90 +and 90. +.PP +You should use \fBpamflip\fP instead for rotations that are a +multiple of a quarter turn. It is faster and more accurate. +.PP +For rotations greater than 45 degrees you may get better results if +you first use \fIpamflip\fP to do a 90 degree rotation and then +\fIpnmrotate\fP less than 45 degrees back the other direction. +.PP +The rotation algorithm is Alan Paeth's three-shear method. Each +shear is implemented by looping over the source pixels and +distributing fractions to each of the destination pixels. This has an +"anti-aliasing" effect - it avoids jagged edges and similar +artifacts. However, it also means that the original colors or gray +levels in the image are modified. If you need to keep precisely the +same set of colors, you can use the \fB-noantialias\fP option. +.PP +The program runs faster and uses less real memory with the +\fB-noantialias\fP option. It uses a large amount of virtual memory +either way, as it keeps a copy of the input image and a copy of the +output image in memory, using 12 bytes per pixel for each. But with +\fB-noantialias\fP, it accesses this memory sequentially in half a +dozen passes, with only a few pages of memory at a time required in +real memory. +.PP +In contrast, without \fB-noantialias\fP, the program's real memory +working set size is one page per input image row plus one page per output +image row. Before Netpbm 10.16 (June 2003), \fB-noantialias\fP had the +same memory requirement. + +.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 +\&), \fBpnmrotate\fP recognizes the following +command line options: +.PP +All options can be abbreviated to their shortest unique prefix. You +may use two hyphens instead of one to designate an option. You may +use either white space or equals signs between an option name and its +value. + + +.TP +\fB-background=\fP\fIcolor\fP +This determines the color of the background on which the rotated image +sits. +.sp +Specify the color (\fIcolor\fP) as described for the +.UR libnetpbm_image.html#colorname +argument of the \fBpnm_parsecolor()\fP library routine +.UE +\&. +.sp +By default, if you don't specify this option, \fBpnmrotate\fP selects +what appears to it to be the background color of the original image. It +determines this color rather simplistically, by taking an average of the colors +of the two top corners of the image. +.sp +This option was new in Netpbm 10.15. Before that, \fBpnmrotate\fP +always behaved as is the default now. + +.TP +\fB-noantialias\fP +This option forces \fBpnmrotate\fP to simply move pixels around instead +of synthesizing output pixels from multiple input pixels. The latter could +cause the output to contain colors that are not in the input, which may not +be desirable. It also probably makes the output contain a large number of +colors. If you need a small number of colors, but it doesn't matter if they +are the exact ones from the input, consider using \fBpnmquant\fP on the +output instead of using \fB-noantialias\fP. +.sp +Note that to ensure the output does not contain colors that are not +in the input, you also must consider the background color. See the +\fB-background\fP option. + + + +.UN references +.SH REFERENCES + +"A Fast Algorithm for General Raster Rotation" by Alan Paeth, +Graphics Interface '86, pp. 77-81. + +.UN seealso +.SH SEE ALSO +.BR "pnmshear" (1)\c +\&, +.BR "pamflip" (1)\c +\&, +.BR "pnmquant" (1)\c +\&, +.BR "pnm" (5)\c +\& + +.UN author +.SH AUTHOR + +Copyright (C) 1989, 1991 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/pnmrotate.html +.PP
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