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 / 
Convert-Color-0.02
River stage two • 18 direct dependents • 36 total dependents
10 ++
/ Convert::Color

NAME

Convert::Color - color space conversions and named lookups

SYNOPSIS

 use Convert::Color;

 my $color = Convert::Color->new( 'hsv:76,0.43,0.89' );

 my ( $red, $green, $blue ) = $color->rgb;

 # GTK uses 16-bit values
 my $gtk_col = Gtk2::Gdk::Color->new( $color->as_rgb16->rgb16 );

 # HTML uses #rrggbb in hex
 my $html = '<td bgcolor="#' . $color->as_rgb8->hex . '">';

DESCRIPTION

This module provides conversions between commonly used ways to express colors. It provides conversions between color spaces such as RGB and HSV, and it provides ways to look up colors by a name.

This class provides a base for subclasses which represent particular color values in particular spaces. The base class provides methods to represent the color in a few convenient forms, though subclasses may provide more specific details for the space in question.

For more detail, read the documentation on these classes; namely:

The following classes are subclasses of one of the above, which provide a way to access predefined colors by names:

CONSTRUCTOR

$color = Convert::Color->new( STRING )

Return a new value to represent the color specified by the string. This string should be prefixed by the name of the color space to which it applies. For example

 rgb:RED,GREEN,BLUE
 rgb8:RRGGBB
 rgb16:RRRRGGGGBBBB
 hsv:HUE,SAT,VAL
 hsl:HUE,SAT,LUM
 cmy:CYAN,MAGENTA,YELLOW
 cmyk:CYAN,MAGENTA,YELLOW,KEY

 vga:NAME
 vga:INDEX

 x11:NAME

For more detail, see the constructor of the color space subclass in question.

METHODS

( $red, $green, $blue ) = $color->rgb

Returns the individual red, green and blue color components of the color value. For RGB values, this is done directly. For values in other spaces, this is done by first converting them to an RGB value using their to_rgb() method.

COLOR SPACE CONVERSIONS

Cross-conversion between color spaces is provided by the convert_to() method, assisted by helper methods in the two color space classes involved.

When converting $color from color space SRC to color space DEST, the following operations are attemped, in this order. SRC and DEST refer to the names of the color spaces, e.g. rgb.

  1. If SRC and DEST are equal, return $color as it stands.

  2. If the SRC space's class provides a convert_to_DEST method, use it.

  3. If the DEST space's class provides a new_from_SRC constructor, call it and pass $color.

  4. If the DEST space's class provides a new_rgb constructor, convert $color to red/green/blue components then call it.

  5. If none of these operations worked, then throw an exception.

These functions may be called in the following ways:

 $other = $color->convert_to_DEST()
 $other = Dest::Class->new_from_SRC( $color )
 $other = Dest::Class->new_rgb( $color->rgb )

$other = $color->convert_to( $space )

Attempt to convert the color into its representation in the given space. See above for the various ways this may be achieved.

AUTOLOADED CONVERSION METHODS

This class provides AUTOLOAD and can behaviour which automatically constructs conversion methods. The following method calls are identical:

 $color->convert_to('rgb')
 $color->as_rgb

The generated method will be stored in the package, so that future calls will not have the AUTOLOAD overhead.

OTHER METHODS

As well as the above, it is likely the subclass will provide accessors to directly obtain the components of its representation in the specific space. For more detail, see the documentation for the specific subclass in question.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>