HLS

The HLS procedure creates a color table based on the HLS (Hue, Lightness, Saturation) color system.

Using the input parameters, a spiral through the double-ended HLS cone is traced. Points along the cone are converted from HLS to RGB. The current colortable (and the COLORS common block) contains the new colortable on exit.

This routine is written in the IDL language. Its source code can be found in the file hls.pro in the lib subdirectory of the IDL distribution.

Calling Sequence

HLS , Litlo, Lithi, Satlo, Sathi, Hue, Loops [, Colr]

Arguments

Litlo

Starting lightness, from 0 to 100%.

Lithi

Ending lightness, from 0 to 100%.

Satlo

Starting saturation, from 0 to 100%.

Sathi

Ending saturation, from 0 to 100%.

Hue

Starting Hue, from 0 to 360 degrees. Red = 0 degs, green = 120, blue = 240.

Loops

The number of loops through the color spiral. This parameter does not have to be an integer. A negative value causes the loops to traverse the spiral in the opposite direction.

Colr

An optional (256,3) integer array in which the new R, G, and B values are returned. Red = Colr [*,0], green = Colr [*,1], blue = Colr [*,2].

See Also

COLOR_CONVERT , HSV , PSEUDO