1Pamhue User Manual(0) Pamhue User Manual(0)
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6 pamhue - change a Netpbm image's hues
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10 pamhue [-huechange=[degrees]] filename
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12 Minimum unique abbreviation of option is acceptable. You may use dou‐
13 ble hyphens instead of single hyphen to denote options. You may use
14 white space in place of the equals sign to separate an option name from
15 its value.
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19 This program is part of Netpbm(1).
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21 pamhue shifts the hue of every pixel in an image by the same amount.
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23 If the image is in a black and white or grayscale format, the image is
24 fully desaturated, so the hue is meaningless and pamhue leaves the
25 image unchanged.
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27 Hue-Saturation-Value, or HSV, is one way to represent a color, like the
28 more well-known RGB. Hue is an indication of the secondary color with
29 the same brightness that most closely approximates the color. A sec‐
30 ondary color is made of a combination of at most two of the primary
31 colors.
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33 In the HSV model, hue is an angular position on the color wheel.
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35 With pamhue, you indicate an angle by which to change all the hues in
36 the image; for example you can say move it 60 degrees clockwise. That
37 would change all red pixels to yellow and all yellow pixels to green,
38 etc.
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41 To modify the saturation and value components of the colors, use pam‐
42 brighten.
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47 To shift the color of each pixel 120 degrees clockwise:
48 pamhue -huechange=120
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50 To shift the color of each pixel 120 degrees counterclockwise:
51 pamhue -huechange=-120
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56 In addition to the options common to all programs based on libnetpbm
57 (most notably -quiet, see
58 Common Options ⟨index.html#commonoptions⟩ ), pamhue recognizes the
59 following command line option:
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63 -huechange=degrees
64 This option specifies the amount to shift each color. It is in
65 degrees, with positive meaning clockwise and negative meaning
66 counterclockwise. It may be fractional and may be more than a
67 full revolution.
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69 This option is mandatory.
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75 pamhue was new in Netpbm 10.86 (March 2019).
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80 pambrighten(1), ppmflash(1), ppmhist(1), ppm(1)
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84 Copyright (C) 2018 by Willem van Schaik. Copyright (C) 1990 by Brian
85 Moffet. Copyright (C) 1989 by Jef Poskanzer.
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87 Permission to use, copy, modify, and distribute this software and its
88 documentation for any purpose and without fee is hereby granted, pro‐
89 vided that the above copyright notice appear in all copies and that
90 both that copyright notice and this permission notice appear in sup‐
91 porting documentation. This software is provided "as is" without
92 express or implied warranty.
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95 This manual page was generated by the Netpbm tool 'makeman' from HTML
96 source. The master documentation is at
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98 http://netpbm.sourceforge.net/doc/pamhue.html
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100netpbm documentation 07 January 2018 Pamhue User Manual(0)