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 separate 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 approximates the color.  A secondary color is made of a combination of at most two
       of the primary 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
        Common Options ⟨index.html#commonoptions⟩ ), 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 supporting 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