Convert::Color::HSV(3)User Contributed Perl DocumentatioConvert::Color::HSV(3)NAME
"Convert::Color::HSV" - a color value represented as
hue/saturation/value
SYNOPSIS
Directly:
use Convert::Color::HSV;
my $red = Convert::Color::HSV->new( 0, 1, 1 );
# Can also parse strings
my $pink = Convert::Color::HSV->new( '0,0.7,1' );
Via Convert::Color:
use Convert::Color;
my $cyan = Convert::Color->new( 'hsv:300,1,1' );
DESCRIPTION
Objects in this class represent a color in HSV space, as a set of three
floating-point values. Hue is stored as a value in degrees, in the
range 0 to 360 (exclusive). Saturation and value are in the range 0 to
1.
This color space may be considered as a cylinder, of height and radius
1. Hue represents the position of the color as the angle around the
axis, the saturation the distance from the axis, and the value the
height above the base. In this shape, the entire base of the cylinder
is pure black, the axis through the centre represents the range of
greys, and the circumference of the top of the cylinder contains the
pure-saturated color wheel, with a pure white point at its centre.
Because the entire bottom surface of this cylinder contains black, a
closely-related color space can be created by reshaping the cylinder
into a cone by contracting the base of the cylinder into a point. The
radius from the axis is called the chroma (though this is a different
definition of "chroma" than that used by CIE).
CONSTRUCTOR
$color = Convert::Color::HSV->new( $hue, $saturation, $value )
Returns a new object to represent the set of values given. The hue
should be in the range 0 to 360 (exclusive), and saturation and value
should be between 0 and 1. Values outside of these ranges will be
clamped.
$color = Convert::Color::HSV->new( $string )
Parses $string for values, and construct a new object similar to the
above three-argument form. The string should be in the form
hue,saturation,value
containing the three floating-point values in decimal notation.
METHODS
$h = $color->hue
$s = $color->saturation
$v = $color->value
Accessors for the three components of the color.
$c = $color->chroma
Returns the derived property of "chroma", which maps the color space
onto a cone instead of a cylinder. This more closely measures the
intuitive concept of how "colorful" the color is than the saturation
value and is useful for distance calculations.
( $hue, $saturation, $value ) = $color->hsv
Returns the individual hue, saturation and value components of the
color value.
$measure = $color->dst_hsv( $other )
Returns a measure of the distance between the two colors. This is the
Euclidean distance between the two colors as points in the chroma-
adjusted cone space.
$measure = $color->dst_hsv_cheap( $other )
Returns a measure of the distance between the two colors. This is used
in the calculation of "dst_hsv" but since it omits the final square-
root and scaling it is cheaper to calculate, for use in cases where
only the relative values matter, such as when picking the "best match"
out of a set of colors. It ranges between 0 for identical colors and 4
for the distance between complementary pure-saturated colors.
SEE ALSO
· Convert::Color - color space conversions
· Convert::Color::RGB - a color value represented as red/green/blue
· <http://en.wikipedia.org/wiki/HSL_and_HSV> - HSL and HSV on
Wikipedia
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.18.2 2014-05-13 Convert::Color::HSV(3)
