\ .\" 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 "Pamcut User Manual" 0 "05 April 2005" "netpbm documentation" .SH NAME pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image .UN synopsis .SH SYNOPSIS \fBpamcut\fP [\fB-left \fP\fIcolnum\fP] [\fB-right \fP\fIcolnum\fP] [\fB-top \fP\fIrownum\fP] [\fB-bottom \fP\fIrownum\fP] [\fB-width \fP\fIcols\fP] [\fB-height \fP\fIrows\fP] [\fB-pad\fP] [\fB-verbose\fP] [\fIleft\fP \fItop\fP \fIwidth\fP \fIheight\fP] [\fIpnmfile\fP] .PP Minimum unique abbreviations of option are 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) . .PP \fBpamcut\fP reads a PAM, PBM, PGM, or PPM image as input and extracts the specified rectangle, and produces the same kind of image as output. .PP There are two ways to specify the rectangle to cut: arguments and options. Options are easier to remember and read, more expressive, and allow you to use defaults. Arguments were the only way available before July 2000. .PP If you use both options and arguments, the two specifications get mixed in an unspecified way. .PP In any case, remember that you are specifying the rectangle to keep, not the bits to discard. Otherwise, you'll be tempted to believe that \fB-right=9\fP means to delete the 9 rightmost columns. (It really means keep the stuff up to Column 9 and delete the rest). .PP To use options, just code any mixture of the \fB-left\fP, \fB-right\fP, \fB-top\fP, \fB-bottom\fP, \fB-width\fP, and \fB-height\fP options. What you don't specify defaults. Those defaults are in favor of minimal cutting and in favor of cutting the right and bottom edges off. It is an error to overspecify, i.e. to specify all three of \fB-left\fP, \fB-right\fP, and \fB-width\fP or \fB-top\fP, \fB-bottom\fP, and \fB-height\fP. .PP To use arguments, specify all four of the \fIleft\fP, \fItop\fP, \fIwidth\fP, and \fIheight\fP arguments. \fIleft\fP and \fItop\fP have the same effect as specifying them as the argument of a \fB-left\fP or \fB-top\fP option, respectively. \fIwidth\fP and \fIheight\fP have the same effect as specifying them as the argument of a \fB-width\fP or \fB-height\fP option, respectively, where they are positive. Where they are not positive, they have the same effect as specifying one less than the value as the argument to a \fB-right\fP or \fB-bottom\fP option, respectively. (E.g. \fIwidth\fP = 0 makes the cut go all the way to the right edge). Before July 2000, negative numbers were not allowed for \fIwidth\fP and \fIheight\fP. .PP Input is from Standard Input if you don't specify the input file \fIpnmfile\fP. .PP Output is to Standard Output. .PP \fBpamcut\fP works on a multi-image stream. It cuts each image in the stream independently and produces a multi-image stream output. Before Netpbm 10.32 (March 2006), it ignored all but the first image in the stream. .PP If you are splitting a single image into multiple same-size images, \fBpamdice\fP is faster and easier than running \fBpamcut\fP multiple times. .PP \fBpamcomp\fP is also useful for cutting and padding an image to a certain size. You create a background image of the desired frame dimensions and overlay the subject image on it. .UN options .SH OPTIONS .TP \fB-left=\fP\fIcolnum\fP The column number of the leftmost column to be in the output. Columns left of this get cut out. If a nonnegative number, it refers to columns numbered from 0 at the left, increasing to the right. If negative, it refers to columns numbered -1 at the right, decreasing to the left. .sp To delete \fIN\fP columns at the left edge, specify \fB-left=\fP\fIN\fP. .sp To delete \fIN\fP columns at the right edge, specify \fB-left=-\fP\fI-(N+1)\fP. .TP \fB-right=\fP\fIcolnum\fP The column number of the rightmost column to be in the output, numbered the same as for \fB-left.\fP Columns to the right of this get cut out. .TP \fB-top=\fP\fIrownum\fP The row number of the topmost row to be in the output. Rows above this get cut out. If a nonnegative number it refers to rows numbered from 0 at the top, increasing downward. If negative, it refers to columns numbered -1 at the bottom, decreasing upward. .sp To delete \fIN\fP rows at the top, specify \fB-top=\fP\fIN\fP. .sp To delete \fIN\fP rows at the bottom, specify \fB-bottom=\fP\fI-(N+1)\fP. .TP \fB-bottom=\fP\fIrownum\fP The row number of the bottom-most row to be in the output, numbered the same as for \fB-top\fP. Rows below this get cut out. .TP \fB-width=\fP\fIcols\fP The number of columns to be in the output. Must be positive. .TP \fB-height=\fP\fIrows\fP The number of rows to be in the output. Must be positive. .TP \fB-pad\fP If the rectangle you specify is not entirely within the input image, \fBpamcut\fP fails unless you also specify \fB-pad\fP. In that case, it pads the output with black up to the edges you specify. You can use this option if you need to have an image of certain dimensions and have an image of arbitrary dimensions. .sp \fBpnmpad\fP also adds borders to an image, but you specify their width directly. .sp \fBpamcomp\fP does a more general form of this padding. Create a background image of the frame dimensions and overlay the subject image on it. You can use options to have the subject image in the center of the frame or against any edge and make the padding any color (the padding color is the color of the background image). .TP \fB-verbose\fP Print information about the processing to Standard Error. .UN seealso .SH SEE ALSO .BR pnmcrop (1) , .BR pamdice (1) , .BR pamcomp (1) , .BR pnmpad (1) , .BR pnmcat (1) , .BR pgmslice (1) , .BR pnm (5) .UN history .SH HISTORY .PP \fBpamcut\fP was derived from \fBpnmcut\fP in Netpbm 9.20 (May 2001). It was the first Netpbm program adapted to the new PAM format and programming library. .PP The predecessor \fBpnmcut\fP was one of the oldest tools in the Netpbm package. .UN author .SH AUTHOR Copyright (C) 1989 by Jef Poskanzer.