"Convert::Color::HSL" - a color value represented as
my $red = Convert::Color::HSL->new( 0, 1, 0.5 );
# Can also parse strings
my $pink = Convert::Color::HSL->new( '0,1,0.8' );
my $cyan = Convert::Color->new( 'hsl:300,1,0.5' );
Objects in this class represent a color in HSL 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 lightness 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 as the distance from the axis, and the lightness 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 entire top of
the cylinder is pure white. The circumference of the circular cross-section
midway along the axis contains the pure-saturated color wheel.
Because both surfaces of this cylinder contain pure black or white discs, a
closely-related color space can be created by reshaping the cylinder into a
bi-cone such that the top and bottom of the cylinder become single points. The
radius from the axis of this shape is called the chroma (though this is a
different definition of "chroma" than that used by CIE).
While the components of this space are called Hue-Chroma-Lightness, it should
not be confused with the similarly-named Hue-Chroma-Luminance (HCL) space.
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 lightness should be between
0 and 1. Values outside of these ranges will be clamped.
Parses $string for values, and construct a new object similar to the above
three-argument form. The string should be in the form
containing the three floating-point values in decimal notation.
Accessors for the three components of the color.
Returns the derived property of "chroma", which maps the color space
onto a bicone 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.
Returns the individual hue, saturation and lightness components of the color
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.
Returns a measure of the distance between the two colors. This is used in the
calculation of "dst_hsl" 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
- <http://en.wikipedia.org/wiki/HSL_and_HSV> - HSL and
HSV on Wikipedia
Paul Evans <email@example.com>