CALL RGBHLS (R, G, B, H, L, S)
void c_rgbhls (float r, float g, float b, float *h,
float *l, float *s)
(REAL, input, range [0.,1.]) represents the red intensity component of the input point in RGB color space.
(REAL, input, range [0.,1.]) represents the green intensity component of the input point in RGB color space.
(REAL, input, range [0.,1.]) represents the blue intensity component of the input point in RGB color space.
(REAL, output, range [0.,360.) ) represents the hue of the input point in HLS color space. A value of (0.,0.,B) in the input space will result in a hue of 0. in the output space.
(REAL, output, range [0.,100.]) represents the lightness value of the input point in HLS color space. Lightness is a measure of the quantity of light - a lightness of 0. is black, and a lightness of 100. gives white. The pure hues occur at lightness value 50.
(REAL, output, range [0.,100.]) represents the saturation value of the input point in HLS color space. Saturation is a measure of how much white light is mixed with the color. Saturation values of 0. represent grays (with a gray value equal to the lightness value L). Saturation values of 100. are fully saturated colors. The hue is undefined when S=0. The fully saturated pure hues occur when S=100. and L=50. The saturation value should be thought of as a percentage.
Use the ncargex command to see the following relevant examples: tcolcv, fcce02.
The C-binding argument descriptions are the same as the FORTRAN argument descriptions.
To use RGBHLS or c_rgbhls, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order.
See the colconv man page for a description of all Colconv error messages and/or informational messages.
Online: colconv, hlsrgb, hsvrgb, rgbhsv, rgbyiq, yiqrgb, ncarg_cbind.
Hardcopy: NCAR Graphics Fundamentals, UNIX Version
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
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