1Pamhue User Manual(0)                                    Pamhue User Manual(0)
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NAME

6       pamhue - change a Netpbm image's hues
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SYNOPSIS

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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DESCRIPTION

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 im‐
25       age 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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EXAMPLES

47       To shift the color of each pixel 120 degrees clockwise:
48       pamhue -huechange=120
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51       To shift the color of each pixel 120 degrees counterclockwise:
52       pamhue -huechange=-120
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OPTIONS

58       In addition to the options common to all programs  based  on  libnetpbm
59       (most notably -quiet, see
60        Common  Options  ⟨index.html#commonoptions⟩  ),  pamhue recognizes the
61       following command line option:
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65       -huechange=degrees
66              This option specifies the amount to shift each color.  It is  in
67              degrees,  with  positive  meaning clockwise and negative meaning
68              counterclockwise.  It may be fractional and may be more  than  a
69              full revolution.
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71              This option is mandatory.
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HISTORY

77       pamhue was new in Netpbm 10.86 (March 2019).
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SEE ALSO

82       pambrighten(1), ppmflash(1), ppmhist(1), ppm(1)
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AUTHOR

86       Copyright  (C)  2018 by Willem van Schaik.  Copyright (C) 1990 by Brian
87       Moffet.  Copyright (C) 1989 by Jef Poskanzer.
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89       Permission to use, copy, modify, and distribute this software  and  its
90       documentation  for  any purpose and without fee is hereby granted, pro‐
91       vided that the above copyright notice appear in  all  copies  and  that
92       both  that  copyright  notice and this permission notice appear in sup‐
93       porting documentation.  This software is provided "as is"  without  ex‐
94       press or implied warranty.
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DOCUMENT SOURCE

97       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
98       source.  The master documentation is at
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100              http://netpbm.sourceforge.net/doc/pamhue.html
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102netpbm documentation            07 January 2018          Pamhue User Manual(0)
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