Manual Reference Pages - CONVERT::COLOR::HSV (3)
"Convert::Color::HSV" - a color value represented as hue/saturation/value
my $red = Convert::Color::HSV->new( 0, 1, 1 );
# Can also parse strings
my $pink = Convert::Color::HSV->new( 0,0.7,1 );
my $cyan = Convert::Color->new( hsv:300,1,1 );
Objects in this class represent a color in HSV space, as a set of three
floating-point values. Hue is stored as a value in degrees, in the range
0 to 360 (exclusive). Saturation and value are in the range 0 to 1.
This color space may be considered as a cylinder, of height and radius 1. Hue
represents the position of the color as the angle around the axis, the
saturation the distance from the axis, and the value the height above the
base. In this shape, the entire base of the cylinder is pure black, the axis
through the centre represents the range of greys, and the circumference of the
top of the cylinder contains the pure-saturated color wheel, with a pure
white point at its centre.
Because the entire bottom surface of this cylinder contains black, a
closely-related color space can be created by reshaping the cylinder into a
cone by contracting the base of the cylinder into a point. The radius from the
axis is called the chroma (though this is a different definition of chroma
than that used by CIE).
CW$color = Convert::Color::HSV->new( CW$hue, CW$saturation, CW$value )
Returns a new object to represent the set of values given. The hue should be
in the range 0 to 360 (exclusive), and saturation and value should be between
0 and 1. Values outside of these ranges will be clamped.
CW$color = Convert::Color::HSV->new( CW$string )
Parses $string for values, and construct a new object similar to the above
three-argument form. The string should be in the form
containing the three floating-point values in decimal notation.
CW$h = CW$color->hue
CW$s = CW$color->saturation
CW$v = CW$color->value
Accessors for the three components of the color.
CW$c = CW$color->chroma
Returns the derived property of chroma, which maps the color space onto a
cone instead of a cylinder. This more closely measures the intuitive concept
of how colorful the color is than the saturation value and is useful for
( CW$hue, CW$saturation, CW$value ) = CW$color->hsv
Returns the individual hue, saturation and value components of the color
CW$measure = CW$color->dst_hsv( CW$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
CW$measure = CW$color->dst_hsv_cheap( CW$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.
Paul Evans <email@example.com>
|perl v5.20.3 ||CONVERT::COLOR::HSV (3) ||2014-06-01 |
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