1Pnmpad User Manual(0) Pnmpad User Manual(0)
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6 pnmpad - add borders to a PNM image
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10 pnmpad [-verbose] [-white|-black] [-width=pixels] [-halign=ratio]
11 [-mwidth=pixels] [-left=pixels] [-right=pixels] [-height=pixels]
12 [-valign=ratio] [-mheight=pixels] [-top=pixels] [-bottom=pixels] [pnm‐
13 file]
14
18 This program is part of Netpbm(1).
19 pnmpad reads a PNM image as input and outputs a PNM image that is the
21 input image plus black or white borders of the sizes specified.
22 If you just need to convert an image to a certain size regardless of
24 the original dimensions, pamcut with the -pad option may be a better
25 choice.
26 pnmmargin does essentially the same thing, but allows you to add bor‐
28 ders of any color and requires all four borders to be the same size.
29
33 All options can be abbreviated to their shortest unique prefix. You
34 may use two hyphens instead of one to designate an option. You may use
35 either white space or an equals sign between an option name and its
36 value.
37 -verbose
41 Verbose output.
42 -white
45 -black Set pad color. Default is -black.
47 -left=pixels
51 -right=pixels
53 -width=width
55 -halign=ratio
57 -mwidth=pixels
59 Specify amount of left and right padding in pixels.
60 -left and -right directly specify the amount of padding added to
62 the left and right sides, respectively, of the image.
63 Alternatively, you can specify -width and just one of -left and
65 -right and pnmpad calculates the required padding on the other
66 side to make the output width pixels wide. If the -width value
67 is less than the width of the input image plus the specified
68 padding, pnmpad ignores -width.
69 If you specify all three of -width, -left, and -right, you must
71 ensure that the -left and -right padding are sufficient to make
72 the image at least as wide as -width specifies. Otherwise, pnm‐
73 pad fails.
74 When you specify -width without -left or -right, and -width is
76 larger than the input image, pnmpad chooses left and right pad‐
77 ding amounts in a certain ratio. That ratio defaults to half,
78 but you can set it to anything (from 0 to 1) with the -halign
79 option. If the input image is already at least as wide as
80 -width specifies, pnmpad adds no padding.
81 Common values for -halign are:
83 0.0 left aligned
86 0.5 center aligned (default)
89 1.0 right aligned
92 -mwidth=pixels says to pad to a multiple of pixels pixels. E.g.
95 if pixels is 10, the output image width will be a multiple of 10
96 pixels. pnmpad adds to whatever padding the other options say
97 to do to get to this multiple. It divides that padding between
98 the left and right sides of the image to maintain the ratio the
99 other options produce. E.g. if you say -left=10 -right=10
100 -mwidth=50 with a 100-pixel image, you end up with a 150-pixel
101 image with the extra padding split evenly between left and right
102 for a total of 25 pixels of padding on the left and 25 on the
103 right.
104 Before Netpbm 10.23 (July 2004), pnmpad did not allow the -left
106 or -right option together with -width.
107 Before Netpbm 10.72 (September 2015), there is no -mwidth.
109 -top=pixels
112 -bottom=pixels
114 -height=height
116 -valign=ratio
118 -mheight=pixels
120 These options determine the vertical padding. They are analo‐
121 gous to the horizontal padding options above.
122
128 Before February 2002, pnmpad had a different option syntax which was
129 less expressive and not like conventional Netpbm programs. That syntax
130 is still understood by pnmpad for backward compatibility, but not docu‐
131 mented or supported for future use.
132
136 pbmmake(1), pnmpaste(1), pamcut(1), pnmcrop(1), pamcomp(1), pnmmar‐
137 gin(1), pbm(1)
138
142 Copyright (C) 2002 by Martin van Beilen
143 Copyright (C) 1990 by Angus Duggan
145 Copyright (C) 1989 by Jef Poskanzer.
147 Permission to use, copy, modify, and distribute this software and its
149 documentation for any purpose and without fee is hereby granted, pro‐
150 vided that the above copyright notice appear in all copies and that
151 both that copyright notice and this permission notice appear in sup‐
152 porting documentation. This software is provided "as is" without
153 express or implied warranty.
154
156 This manual page was generated by the Netpbm tool 'makeman' from HTML
157 source. The master documentation is at
158 http://netpbm.sourceforge.net/doc/pnmpad.html
160netpbm documentation 18 October 2018 Pnmpad User Manual(0)