Page 207 - Computational Colour Science Using MATLAB

194 COLOUR TOOLBOX

% lt is the luminance of the adapting test field
% and has default value of 100
% lw is the luminance of the adapting reference field
% and has default value of 100
% xyzc contains the tristimulus values of the
% stimulus under the reference illuminant

11.17 ciecam97s.m (Box 17)

% function [j,c,hq,m,h,s,q,cd]=ciecam97s(xyz,xyzw,
la,yb,para)
% implements the CIECAM97s colour appearance model
% operates on 1 by 3 matrix xyz containing tristimulus
% values of the stimulus under the test illuminant
% xyzt and xyzr are 1 by 3 matrices containing the
% white points for the test and reference conditions
% la and yb are the luminance and Y tristimulus values of
% the achromatic background against which the sample is
% viewed
% para is a 1 by 4 matrix containing c, Nc, Fll and F

11.18 gogtest.m (Box 18)

% function [err] = gogtest(gogs,dacs,rgbs)
% computes the error between measured and predicted
% linearized dac values for a given set of GOG values
% gogs is a 2 by 1 matrix that contains the gamma and gain
% dacs is an n by 1 matrix that contains the actual RGB values
% obtained by dividing the RGB values by 255
% rgbs is an n by 1 matrix that is obtained from a linear
% transform of measured XYZ values