"Convert::Color::HSV" - a color value represented as
hue/saturation/value
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' );
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).
$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.
$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.
- •
- 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
Paul Evans <
[email protected]>