man > pamhue(1)

Pamhue User Manual(1)                  General Commands Manual                 Pamhue User Manual(1)

NAME
       pamhue - change a Netpbm image's hues


SYNOPSIS
       pamhue [-huechange=[degrees]] filename

       Minimum  unique  abbreviation of option is 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 sep‐
       arate an option name from its value.


DESCRIPTION
       This program is part of Netpbm(1).

       pamhue shifts the hue of every pixel in an image by the same amount.

       If the image is in a black and white or grayscale format, the image is fully desaturated,  so
       the hue is meaningless and pamhue leaves the image unchanged.

       Hue-Saturation-Value,  or HSV, is one way to represent a color, like the more well-known RGB.
       Hue is an indication of the secondary color with the same brightness that  most  closely  ap‐
       proximates  the color.  A secondary color is made of a combination of at most two of the pri‐
       mary colors.

       In the HSV model, hue is an angular position on the color wheel.

       With pamhue, you indicate an angle by which to change all the hues in the image; for  example
       you can say move it 60 degrees clockwise.  That would change all red pixels to yellow and all
       yellow pixels to green, etc.


       To modify the saturation and value components of the colors, use pambrighten.



EXAMPLES
       To shift the color of each pixel 120 degrees clockwise:
       pamhue -huechange=120


       To shift the color of each pixel 120 degrees counterclockwise:
       pamhue -huechange=-120




OPTIONS
       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet,
       see ]8;;index.html#commonoptions\ Common Options]8;;\ ), pamhue recognizes the following command line option:



       -huechange=degrees
              This option specifies the amount to shift each color.  It is in degrees, with positive
              meaning clockwise and negative meaning counterclockwise.  It may be fractional and may
              be more than a full revolution.

              This option is mandatory.




HISTORY
       pamhue was new in Netpbm 10.86 (March 2019).



SEE ALSO
       pambrighten(1), ppmflash(1), ppmhist(1), ppm(1)


AUTHOR
       Copyright (C) 2018 by Willem van Schaik.  Copyright (C) 1990 by Brian Moffet.  Copyright  (C)
       1989 by Jef Poskanzer.

       Permission  to  use, copy, modify, and distribute this software and its documentation for any
       purpose and without fee is hereby granted, provided that the above copyright notice appear in
       all copies and that both that copyright notice and this permission notice appear in  support‐
       ing documentation.  This software is provided "as is" without express or implied warranty.

DOCUMENT SOURCE
       This  manual  page  was  generated by the Netpbm tool 'makeman' from HTML source.  The master
       documentation is at

              http://netpbm.sourceforge.net/doc/pamhue.html

netpbm documentation                       07 January 2018                     Pamhue User Manual(1)