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Convert::Color(3)     User Contributed Perl Documentation    Convert::Color(3)

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:

       o   Convert::Color::RGB - red/green/blue	as floats between 0 and	1

       o   Convert::Color::RGB8	- red/green/blue as 8-bit integers

       o   Convert::Color::RGB16 - red/green/blue as 16-bit integers

       o   Convert::Color::HSV - hue/saturation/value

       o   Convert::Color::HSL - hue/saturation/lightness

       o   Convert::Color::CMY - cyan/magenta/yellow

       o   Convert::Color::CMYK	- cyan/magenta/yellow/key (blackness)

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

       o   Convert::Color::VGA - named lookup for the basic VGA	colors

       o   Convert::Color::X11 - named lookup of colors	from X11's rgb.txt

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.

       If the relevant subclass	has already been loaded	(either	explicitly, or
       implicitly by either the	"new" or "convert_to" methods),	then a
       specific	conversion method will be installed in the class.

	$other = $color->as_$space

       Methods of this form are	currently "AUTOLOAD"ed if they do not yet
       exist, but this feature should not be relied upon - see below.

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.

       This feature is deprecated and should not be relied upon, due to	the
       delicate	nature of "AUTOLOAD".

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.

SUBCLASS METHODS
       This base class is intended to be subclassed to provide more color
       spaces.

   $class->register_color_space( $space	)
       A subclass should call this method to register itself as	a named	color
       space.

   $class->register_palette( %args )
       A subclass that provides	a fixed	set of color values should call	this
       method, to set up automatic conversions that look for the closest match
       within the set. This conversion process is controlled by	the %args:

       enumerate => STRING or CODE
	       A method	name or	anonymous CODE reference which will be used to
	       generate	the list of color values.

       enumerate_once => STRING	or CODE
	       As per "enumerate", but will be called only once	and the
	       results cached.

       This method creates a new class method on the calling package, called
       "closest_to".

       $color =	$pkg-_closest_to( $orig, $space	)

       Returns the color in the	space closest to the given value. The distance
       is measured in the named	space; defaulting to "rgb" if this is not
       provided.

       In the case of a	tie, where two or more colors have the same distance
       from the	target,	the first one will be chosen.

AUTHOR
       Paul Evans <leonerd@leonerd.org.uk>

perl v5.24.1			  2014-06-01		     Convert::Color(3)

NAME | SYNOPSIS | DESCRIPTION | CONSTRUCTOR | METHODS | COLOR SPACE CONVERSIONS | AUTOLOADED CONVERSION METHODS | OTHER METHODS | SUBCLASS METHODS | AUTHOR

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