This function converts a matrix of PostScript RGB (Red - Green - Blue)
specifications to HSB (Hue - Saturation - Brightness) specifications.
USAGE:
ps.rgb2hsb(rgb)
REQUIRED ARGUMENTS:
rgb:
Numeric matrix where each row corresponds to a color specification and each
column corresponds to one of the RGB color model components. Each color
component should be in the range of 0.0 through 1.0.
VALUE:
Each color is converted to an equivalent HSB color model specification and a
matrix of the same size as rgb is returned. Each component of the HSB
specification will also be in the range of 0.0 to 1.0.
DETAILS:
The algorithm for ps.rgb2hsb was adapted from the "RGB to HSV" conversion
algorithm in Foley (1990).
REFERENCES:
Foley, van Dam, Feiner, Hughes (1990).
Computer Graphics: Principles and Practice, second edition
Addison-Wesley, Reading, Massachusetts