1Pamcut User Manual(0) Pamcut User Manual(0)
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6 pamcut - cut a rectangle out of a PAM, PBM, PGM, or PPM image
7
10 pamcut
11 [-left colnum]
13 [-right colnum]
15 [-top rownum]
17 [-bottom rownum]
19 [-width cols]
21 [-height rows]
23 [-pad]
25 [-verbose]
27 [left top width height]
29 [pnmfile]
31
34 This program is part of Netpbm(1).
35 pamcut reads a PAM, PBM, PGM, or PPM image as input and extracts the
37 specified rectangle, and produces the same kind of image as output.
38 Minimum unique abbreviations of option are acceptable. You may use
40 double hyphens instead of single hyphen to denote options. You may use
41 white space in place of the equals sign to separate an option name from
42 its value.
43 There are two ways to specify the rectangle to cut: arguments and
45 options. Options are easier to remember and read, more expressive, and
46 allow you to use defaults. Arguments were the only way available
47 before July 2000.
48 If you use both options and arguments, the two specifications get mixed
50 in an unspecified way.
51 In any case, remember that you are specifying the rectangle to keep,
53 not the bits to discard. Otherwise, you'll be tempted to believe that
54 -right=9 means to delete the 9 rightmost columns. (It really means
55 keep the stuff up to Column 9 and delete the rest).
56 To use options, just code any mixture of the -left, -right, -top, -bot‐
58 tom, -width, and -height options. What you don't specify defaults.
59 Those defaults are in favor of minimal cutting and in favor of cutting
60 the right and bottom edges off. It is an error to overspecify, i.e. to
61 specify all three of -left, -right, and -width or -top, -bottom, and
62 -height.
63 To use arguments, specify all four of the left, top, width, and height
65 arguments. left and top have the same effect as specifying them as the
66 argument of a -left or -top option, respectively. width and height
67 have the same effect as specifying them as the argument of a -width or
68 -height option, respectively, where they are positive. Where they are
69 not positive, they have the same effect as specifying one less than the
70 value as the argument to a -right or -bottom option, respectively.
71 (E.g. width = 0 makes the cut go all the way to the right edge).
72 Before July 2000, negative numbers were not allowed for width and
73 height.
74 Input is from Standard Input if you don't specify the input file pnm‐
76 file.
77 Output is to Standard Output.
79 pamcut works on a multi-image stream. It cuts each image in the stream
81 independently and produces a multi-image stream output. Before Netpbm
82 10.32 (March 2006), it ignored all but the first image in the stream.
83 If you are splitting a single image into multiple same-size images,
85 pamdice is faster and easier than running pamcut multiple times.
86 pamcomp is also useful for cutting and padding an image to a certain
88 size. You create a background image of the desired frame dimensions
89 and overlay the subject image on it.
90
93 -left=colnum
94 The column number of the leftmost column to be in the output.
95 Columns left of this get cut out. If a nonnegative number, it
96 refers to columns numbered from 0 at the left, increasing to the
97 right. If negative, it refers to columns numbered -1 at the
98 right, decreasing to the left.
99 To delete N columns at the left edge, specify -left=N.
101 To delete N columns at the right edge, specify -left=--(N+1).
103 -right=colnum
106 The column number of the rightmost column to be in the output,
107 numbered the same as for -left. Columns to the right of this
108 get cut out.
109 -top=rownum
112 The row number of the topmost row to be in the output. Rows
113 above this get cut out. If a nonnegative number it refers to
114 rows numbered from 0 at the top, increasing downward. If nega‐
115 tive, it refers to columns numbered -1 at the bottom, decreasing
116 upward.
117 To delete N rows at the top, specify -top=N.
119 To delete N rows at the bottom, specify -bottom=-(N+1).
121 -bottom=rownum
124 The row number of the bottom-most row to be in the output, num‐
125 bered the same as for -top. Rows below this get cut out.
126 -width=cols
129 The number of columns to be in the output. Must be positive.
130 -height=rows
133 The number of rows to be in the output. Must be positive.
134 -pad If the rectangle you specify is not entirely within the input
137 image, pamcut fails unless you also specify -pad. In that case,
138 it pads the output with black up to the edges you specify. You
139 can use this option if you need to have an image of certain
140 dimensions and have an image of arbitrary dimensions.
141 pnmpad also adds borders to an image, but you specify their
143 width directly.
144 pamcomp does a more general form of this padding. Create a
146 background image of the frame dimensions and overlay the subject
147 image on it. You can use options to have the subject image in
148 the center of the frame or against any edge and make the padding
149 any color (the padding color is the color of the background
150 image).
151 -verbose
154 Print information about the processing to Standard Error.
155
159 pnmcrop(1), pamdice(1), pamcomp(1), pnmpad(1), pnmcat(1), pgmslice(1),
160 pnm(1)
161
164 pamcut was derived from pnmcut in Netpbm 9.20 (May 2001). It was the
165 first Netpbm program adapted to the new PAM format and programming
166 library.
167 The predecessor pnmcut was one of the oldest tools in the Netpbm pack‐
169 age.
170
174 Copyright (C) 1989 by Jef Poskanzer.
175netpbm documentation 05 April 2005 Pamcut User Manual(0)