Imager::Color(3)

NAME
Imager::Color - Color handling for Imager.

SYNOPSIS
  $color = Imager::Color->new($red, $green, $blue);
  $color = Imager::Color->new($red, $green, $blue, $alpha);
  $color = Imager::Color->new("#C0C0FF"); # html color specification
  $color->set($red, $green, $blue);
  $color->set($red, $green, $blue, $alpha);
  $color->set("#C0C0FF"); # html color specification
  ($red, $green, $blue, $alpha) = $color->rgba();
  @hsv = $color->hsv(); # not implemented but proposed
  $color->info();

DESCRIPTION
This module handles creating color objects used by imager. The idea is that in the future this module will be able to handle colorspace calculations as well. This creates a color object to pass to functions that need a color argument. This changes an already defined color. Note that this does not affect any places where the color has been used previously. This returns the rgba code of the color the object contains. Calling info merely dumps the relevant colorcode to the log.

You can specify colors in several different ways, you can just supply simple values: simple numeric parameters - if you supply 3 or 4 numeric arguments, you get a color made up of those RGB (and possibly A) components. a six hex digit web color, either 'RRGGBB' or '#RRGGBB' an eight hex digit web color, either 'RRGGBBAA' or '#RRGGBBAA'. a 3 hex digit web color, '#RGB' - a value of F becomes 255. a color name, from whichever of the gimp Named_Colors file or X rgb.txt is found first. The same as using the name keyword.

You can supply named parameters: 'red', 'green' and 'blue', optionally shortened to 'r', 'g' and 'b'. The color components in the range 0 to 255.

 # all of the following are equivalent
 my $c1 = Imager::Color->new(red=>100, blue=>255, green=>0);
 my $c2 = Imager::Color->new(r=>100, b=>255, g=>0);
 my $c3 = Imager::Color->new(r=>100, blue=>255, g=>0);
'hue', 'saturation' and 'value', optionally shortened to 'h', 's' and 'v', to specify a HSV color. 0 <= hue < 360, 0 <= s <= 1 and 0 <= v <= 1.

  # the same as RGB(127,255,127)
  my $c1 = Imager::Color->new(hue=>120, v=>1, s=>0.5);
  my $c1 = Imager::Color->new(hue=>120, value=>1, saturation=>0.5);
'web', which can specify a 6 or 3 hex digit web color, in any of the forms '#RRGGBB', '#RGB', 'RRGGBB' or 'RGB'.

  my $c1 = Imager::Color->new(web=>'#FFC0C0'); # pale red
'gray' or 'grey' which specifies a single channel, from 0 to 255.

  # exactly the same
  my $c1 = Imager::Color->new(gray=>128);
  my $c1 = Imager::Color->new(grey=>128);
'rgb' which takes a 3 member arrayref, containing each of the red, green and blue values.

  # the same
  my $c1 = Imager::Color->new(rgb=>[255, 100, 0]);
  my $c1 = Imager::Color->new(r=>255, g=>100, b=>0);
'hsv' which takes a 3 member arrayref, containting each of hue, saturation and value.

  # the same
  my $c1 = Imager::Color->new(hsv=>[120, 0.5, 1]);
  my $c1 = Imager::Color->new(hue=>120, v=>1, s=>0.5);
'gimp' which specifies a color from a GIMP palette file. You can specify the filename of the palette file with the 'palette' parameter, or let Imager::Color look in various places, typically "$HOME/gimp-1.x/palettes/Named_Colors" with and without the version number, and in /usr/share/gimp/palettes/. The palette file must have color names.

  my $c1 = Imager::Color->new(gimp=>'snow');
  my $c1 = Imager::Color->new(gimp=>'snow', palette=>'testimg/test_gimp_pal);
'xname' which specifies a color from an X11 rgb.txt file. You can specify the filename of the rgb.txt file with the 'palette' parameter, or let Imager::Color look in various places, typically '/usr/lib/X11/rgb.txt'.

  my $c1 = Imager::Color->new(xname=>'blue') # usually RGB(0, 0, 255)
'name' which specifies a name from either a GIMP palette or an X rgb.txt file, whichever is found first. 'channel0', 'channel1', etc, each of which specifies a single channel. These can be abbreviated to 'c0', 'c1' etc. 'channels' which takes an arrayref of the channel values.

Optionally you can add an alpha channel to a color with the 'alpha' or 'a' parameter.

These color specifications can be used for both constructing new colors with the new() method and modifying existing colors with the set() method.

AUTHOR
Arnar M. Hrafnkelsson, addi@umich.edu And a great deal of help from others - see the README for a complete list.

SEE ALSO
Imager(3) http://www.eecs.umich.edu/~addi/perl/Imager/