ncl_rgbhsv man page
RGBHSV — Converts a color specification given in the Red, Green, Blue (RGB) color space to color values in the Hue, Saturation, and Value (HSV) color space.
CALL RGBHSV (R, G, B, H, S, V)
void c_rgbhsv (float r, float g, float b, float *h,
float *s, float *v)
(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 HSV color space. A value of (R,0.,0.) in the input space will result in a hue of 0. in the output space.
(REAL, output, range [0.,1.]) represents the saturation value of the input point in HSV 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 V). Saturation values of 1. are fully saturated colors. The hue is technically undefined when S=0.; the code leaves H at its previous value when S=0. (0. initially). The fully saturated pure hues occur when S=1. and V=1.
(REAL, output, range [0.,1.]) represents the value in HSV space.
The C-binding argument descriptions are the same as the FORTRAN argument descriptions.
Use the ncargex command to see the following relevant examples: tcolcv, fcce02.
To use RGBHSV or c_rgbhsv, 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, rgbhls, rgbyiq, yiqrgb, ncarg_cbind.
Hardcopy: NCAR Graphics Fundamentals, UNIX Version
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.