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| | /* Interface to Little CMS
Copyright (C) 2017 Mark Oteiza <mvoteiza@udel.edu>
This file is NOT part of GNU Emacs.
GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#ifdef HAVE_LCMS2
#include <lcms2.h>
#include <math.h>
#include "lisp.h"
static bool
parse_lab_list (Lisp_Object lab_list, cmsCIELab *color)
{
#define PARSE_LAB_LIST_FIELD(field) \
if (CONSP (lab_list) && NUMBERP (XCAR (lab_list))) \
{ \
color->field = XFLOATINT (XCAR (lab_list)); \
lab_list = XCDR (lab_list); \
} \
else \
return false;
PARSE_LAB_LIST_FIELD (L);
PARSE_LAB_LIST_FIELD (a);
PARSE_LAB_LIST_FIELD (b);
return true;
}
/* http://www.ece.rochester.edu/~gsharma/ciede2000/ciede2000noteCRNA.pdf> */
DEFUN ("lcms-cie-de2000", Flcms_cie_de2000, Slcms_cie_de2000, 2, 2, 0,
doc: /* Compute CIEDE2000 metric distance between COLOR1 and COLOR2.
Each color is a list of L*a*b* coordinates, where the L* channel ranges from
0 to 100, and the a* and b* channels range from -128 to 128.
Optional arguments KL, KC, KH are weighting parameters for lightness,
chroma, and hue, respectively. */)
(Lisp_Object color1, Lisp_Object color2)
{
cmsCIELab Lab1, Lab2;
if (!(CONSP (color1) && parse_lab_list (color1, &Lab1)))
signal_error ("Invalid color", color1);
if (!(CONSP (color2) && parse_lab_list (color2, &Lab2)))
signal_error ("Invalid color", color1);
return make_float (cmsCIE2000DeltaE (&Lab1, &Lab2, 1.0f, 1.0f, 1.0f));
}
/* FIXME: code duplication */
static bool
parse_xyz_list (Lisp_Object xyz_list, cmsCIEXYZ *color)
{
#define PARSE_XYZ_LIST_FIELD(field) \
if (CONSP (xyz_list) && NUMBERP (XCAR (xyz_list))) \
{ \
color->field = XFLOATINT (XCAR (xyz_list)); \
xyz_list = XCDR (xyz_list); \
} \
else \
return false;
PARSE_XYZ_LIST_FIELD (X);
PARSE_XYZ_LIST_FIELD (Y);
PARSE_XYZ_LIST_FIELD (Z);
return true;
}
DEFUN ("lcms-cam02-ucs", Flcms-cam02-ucs, Slcms_cam02_ucs, 2, 2, 0,
doc: /* Compute CAM02-UCS metric distance between COLOR1 and COLOR2.
Each color is a list of XYZ coordinates.
Optional argument is the XYZ white point, which defaults to D65. */)
(Lisp_Object color1, Lisp_Object color2)
{
cmsViewingConditions vc;
cmsJCh jch1, jch2;
cmsHANDLE h1, h2;
cmsCIEXYZ xyz1, xyz2;
double Jp1, ap1, bp1, Jp2, ap2, bp2;
double Mp1, Mp2, FL, k;
if (!(CONSP (color1) && parse_xyz_list (color1, &xyz1)))
signal_error ("Invalid color", color1);
if (!(CONSP (color2) && parse_xyz_list (color2, &xyz2)))
signal_error ("Invalid color", color1);
vc.whitePoint.X = 95.047;
vc.whitePoint.Y = 100.00;
vc.whitePoint.Z = 108.883;
vc.Yb = 20;
vc.La = 100;
vc.surround = AVG_SURROUND;
vc.D_value = 1.0;
h1 = cmsCIECAM02Init(0, &vc);
h2 = cmsCIECAM02Init(0, &vc);
cmsCIECAM02Forward(h1, &xyz1, &jch1);
cmsCIECAM02Forward(h2, &xyz2, &jch2);
cmsCIECAM02Done(h1);
cmsCIECAM02Done(h2);
/* Now have JCh, need to calculate Jab
M = C * F_L^0.25
J' = 1.7 J / (1 + 0.007 J)
M' = 43.86 ln(1 + 0.0228 M)
a' = M' cos(h)
b' = M' sin(h)
where
F_L = 0.2 k^4 (5 L_A) + 0.1 (1 - k^4)^2 (5 L_A)^(1/3),
k = 1/(5 L_A + 1)
*/
k = 1.0f / (1.0f + (5.0f * vc.La));
FL = pow(k, 4) * vc.La +
0.1f * pow(1 - pow(k, 4), 2) * pow(5.0f * vc.La, 1.0f / 3.0f);
Mp1 = 43.86f * log(1.0f + 0.0228f * (jch1.C * pow(FL, 0.25)));
Mp2 = 43.86f * log(1.0f + 0.0228f * (jch2.C * pow(FL, 0.25)));
Jp1 = 1.7f * jch1.J / (1.0f + (0.007f * jch1.J));
Jp2 = 1.7f * jch2.J / (1.0f + (0.007f * jch2.J));
ap1 = Mp1 * cos(jch1.h);
ap2 = Mp2 * cos(jch2.h);
bp1 = Mp1 * sin(jch1.h);
bp2 = Mp2 * sin(jch2.h);
return make_float(sqrt(pow(Jp2 - Jp1, 2) +
pow(ap2 - ap1, 2) +
pow(bp2 - bp1, 2)));
}
\f
/* Initialization */
void
syms_of_lcms2 (void)
{
defsubr (&Slcms_cie_de2000);
defsubr (&Slcms_cam02_ucs);
}
#endif /* HAVE_LCMS2 */
|