d24ec58540
Also add tests from the colorspacious library. Finally, catch an errant calculation, where degrees were not being converted to radians. * src/lcms.c (deg2rad, default_viewing_conditions): (parse_viewing_conditions): New functions. (lcms-cam02-ucs): Add comments pointing to references used. Expand the docstring and explain viewing conditions. JCh hue is given in degrees and needs to be converted to radians. (lcms-d65-xyz): Remove. No need to duplicate this in Lisp or make the API needlessly impure. * test/src/lcms-tests.el: Reword commentary. (lcms-rgb255->xyz): New function. (lcms-cri-cam02-ucs): Fix let-binding. (lcms-dE-cam02-ucs-silver): New test, assimilated from colorspacious.
370 lines
11 KiB
C
370 lines
11 KiB
C
/* Interface to Little CMS
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Copyright (C) 2017 Free Software Foundation, Inc.
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This file is part of GNU Emacs.
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GNU Emacs is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or (at
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your option) any later version.
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GNU Emacs is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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#ifdef HAVE_LCMS2
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#include <lcms2.h>
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#include <math.h>
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#include "lisp.h"
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#ifdef WINDOWSNT
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# include <windows.h>
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# include "w32.h"
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DEF_DLL_FN (cmsFloat64Number, cmsCIE2000DeltaE,
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(const cmsCIELab* Lab1, const cmsCIELab* Lab2, cmsFloat64Number Kl,
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cmsFloat64Number Kc, cmsFloat64Number Kh));
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DEF_DLL_FN (cmsHANDLE, cmsCIECAM02Init,
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(cmsContext ContextID, const cmsViewingConditions* pVC));
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DEF_DLL_FN (void, cmsCIECAM02Forward,
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(cmsHANDLE hModel, const cmsCIEXYZ* pIn, cmsJCh* pOut));
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DEF_DLL_FN (void, cmsCIECAM02Done, (cmsHANDLE hModel));
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DEF_DLL_FN (cmsBool, cmsWhitePointFromTemp,
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(cmsCIExyY* WhitePoint, cmsFloat64Number TempK));
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DEF_DLL_FN (void, cmsxyY2XYZ, (cmsCIEXYZ* Dest, const cmsCIExyY* Source));
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static bool lcms_initialized;
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static bool
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init_lcms_functions (void)
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{
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HMODULE library = w32_delayed_load (Qlcms2);
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if (!library)
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return false;
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LOAD_DLL_FN (library, cmsCIE2000DeltaE);
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LOAD_DLL_FN (library, cmsCIECAM02Init);
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LOAD_DLL_FN (library, cmsCIECAM02Forward);
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LOAD_DLL_FN (library, cmsCIECAM02Done);
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LOAD_DLL_FN (library, cmsWhitePointFromTemp);
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LOAD_DLL_FN (library, cmsxyY2XYZ);
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return true;
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}
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# undef cmsCIE2000DeltaE
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# undef cmsCIECAM02Init
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# undef cmsCIECAM02Forward
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# undef cmsCIECAM02Done
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# undef cmsWhitePointFromTemp
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# undef cmsxyY2XYZ
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# define cmsCIE2000DeltaE fn_cmsCIE2000DeltaE
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# define cmsCIECAM02Init fn_cmsCIECAM02Init
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# define cmsCIECAM02Forward fn_cmsCIECAM02Forward
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# define cmsCIECAM02Done fn_cmsCIECAM02Done
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# define cmsWhitePointFromTemp fn_cmsWhitePointFromTemp
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# define cmsxyY2XYZ fn_cmsxyY2XYZ
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#endif /* WINDOWSNT */
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static bool
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parse_lab_list (Lisp_Object lab_list, cmsCIELab *color)
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{
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#define PARSE_LAB_LIST_FIELD(field) \
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if (CONSP (lab_list) && NUMBERP (XCAR (lab_list))) \
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{ \
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color->field = XFLOATINT (XCAR (lab_list)); \
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lab_list = XCDR (lab_list); \
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} \
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else \
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return false;
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PARSE_LAB_LIST_FIELD (L);
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PARSE_LAB_LIST_FIELD (a);
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PARSE_LAB_LIST_FIELD (b);
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return true;
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}
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/* http://www.ece.rochester.edu/~gsharma/ciede2000/ciede2000noteCRNA.pdf> */
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DEFUN ("lcms-cie-de2000", Flcms_cie_de2000, Slcms_cie_de2000, 2, 5, 0,
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doc: /* Compute CIEDE2000 metric distance between COLOR1 and COLOR2.
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Each color is a list of L*a*b* coordinates, where the L* channel ranges from
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0 to 100, and the a* and b* channels range from -128 to 128.
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Optional arguments KL, KC, KH are weighting parameters for lightness,
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chroma, and hue, respectively. The parameters each default to 1. */)
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(Lisp_Object color1, Lisp_Object color2,
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Lisp_Object kL, Lisp_Object kC, Lisp_Object kH)
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{
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cmsCIELab Lab1, Lab2;
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cmsFloat64Number Kl, Kc, Kh;
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#ifdef WINDOWSNT
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if (!lcms_initialized)
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lcms_initialized = init_lcms_functions ();
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if (!lcms_initialized)
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{
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message1 ("lcms2 library not found");
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return Qnil;
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}
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#endif
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if (!(CONSP (color1) && parse_lab_list (color1, &Lab1)))
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signal_error ("Invalid color", color1);
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if (!(CONSP (color2) && parse_lab_list (color2, &Lab2)))
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signal_error ("Invalid color", color1);
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if (NILP (kL))
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Kl = 1.0f;
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else if (!(NUMBERP (kL) && (Kl = XFLOATINT(kL))))
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wrong_type_argument(Qnumberp, kL);
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if (NILP (kC))
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Kc = 1.0f;
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else if (!(NUMBERP (kC) && (Kc = XFLOATINT(kC))))
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wrong_type_argument(Qnumberp, kC);
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if (NILP (kL))
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Kh = 1.0f;
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else if (!(NUMBERP (kH) && (Kh = XFLOATINT(kH))))
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wrong_type_argument(Qnumberp, kH);
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return make_float (cmsCIE2000DeltaE (&Lab1, &Lab2, Kl, Kc, Kh));
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}
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static double
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deg2rad (double degrees)
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{
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return M_PI * degrees / 180.0;
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}
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static cmsCIEXYZ illuminant_d65 = { .X = 95.0455, .Y = 100.0, .Z = 108.8753 };
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static void
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default_viewing_conditions (const cmsCIEXYZ *wp, cmsViewingConditions *vc)
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{
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vc->whitePoint.X = wp->X;
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vc->whitePoint.Y = wp->Y;
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vc->whitePoint.Z = wp->Z;
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vc->Yb = 20;
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vc->La = 100;
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vc->surround = AVG_SURROUND;
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vc->D_value = 1.0;
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}
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/* FIXME: code duplication */
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static bool
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parse_xyz_list (Lisp_Object xyz_list, cmsCIEXYZ *color)
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{
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#define PARSE_XYZ_LIST_FIELD(field) \
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if (CONSP (xyz_list) && NUMBERP (XCAR (xyz_list))) \
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{ \
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color->field = 100.0 * XFLOATINT (XCAR (xyz_list)); \
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xyz_list = XCDR (xyz_list); \
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} \
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else \
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return false;
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PARSE_XYZ_LIST_FIELD (X);
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PARSE_XYZ_LIST_FIELD (Y);
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PARSE_XYZ_LIST_FIELD (Z);
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return true;
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}
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static bool
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parse_viewing_conditions (Lisp_Object view, const cmsCIEXYZ *wp,
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cmsViewingConditions *vc)
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{
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#define PARSE_VIEW_CONDITION_FLOAT(field) \
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if (CONSP (view) && NUMBERP (XCAR (view))) \
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{ \
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vc->field = XFLOATINT (XCAR (view)); \
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view = XCDR (view); \
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} \
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else \
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return false;
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#define PARSE_VIEW_CONDITION_INT(field) \
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if (CONSP (view) && NATNUMP (XCAR (view))) \
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{ \
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CHECK_RANGED_INTEGER (XCAR (view), 1, 4); \
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vc->field = XINT (XCAR (view)); \
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view = XCDR (view); \
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} \
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else \
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return false;
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PARSE_VIEW_CONDITION_FLOAT (Yb);
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PARSE_VIEW_CONDITION_FLOAT (La);
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PARSE_VIEW_CONDITION_INT (surround);
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PARSE_VIEW_CONDITION_FLOAT (D_value);
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if (! NILP (view))
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return false;
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vc->whitePoint.X = wp->X;
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vc->whitePoint.Y = wp->Y;
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vc->whitePoint.Z = wp->Z;
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return true;
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}
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/* References:
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Li, Luo et al. "The CRI-CAM02UCS colour rendering index." COLOR research
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and application, 37 No.3, 2012.
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Luo et al. "Uniform colour spaces based on CIECAM02 colour appearance
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model." COLOR research and application, 31 No.4, 2006. */
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DEFUN ("lcms-cam02-ucs", Flcms_cam02_ucs, Slcms_cam02_ucs, 2, 4, 0,
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doc: /* Compute CAM02-UCS metric distance between COLOR1 and COLOR2.
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Each color is a list of XYZ tristimulus values, with Y scaled about unity.
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Optional argument WHITEPOINT is the XYZ white point, which defaults to
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illuminant D65.
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Optional argument VIEW is a list containing the viewing conditions, and
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is of the form (YB LA SURROUND DVALUE) where SURROUND corresponds to
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1 AVG_SURROUND
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2 DIM_SURROUND
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3 DARK_SURROUND
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4 CUTSHEET_SURROUND
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The default viewing conditions are (20 100 1 1). */)
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(Lisp_Object color1, Lisp_Object color2, Lisp_Object whitepoint,
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Lisp_Object view)
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{
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cmsViewingConditions vc;
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cmsJCh jch1, jch2;
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cmsHANDLE h1, h2;
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cmsCIEXYZ xyz1, xyz2, xyzw;
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double Jp1, ap1, bp1, Jp2, ap2, bp2;
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double Mp1, Mp2, FL, k, k4;
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#ifdef WINDOWSNT
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if (!lcms_initialized)
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lcms_initialized = init_lcms_functions ();
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if (!lcms_initialized)
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{
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message1 ("lcms2 library not found");
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return Qnil;
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}
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#endif
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if (!(CONSP (color1) && parse_xyz_list (color1, &xyz1)))
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signal_error ("Invalid color", color1);
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if (!(CONSP (color2) && parse_xyz_list (color2, &xyz2)))
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signal_error ("Invalid color", color2);
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if (NILP (whitepoint))
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xyzw = illuminant_d65;
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else if (!(CONSP (whitepoint) && parse_xyz_list (whitepoint, &xyzw)))
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signal_error ("Invalid white point", whitepoint);
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if (NILP (view))
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default_viewing_conditions (&xyzw, &vc);
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else if (!(CONSP (view) && parse_viewing_conditions (view, &xyzw, &vc)))
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signal_error ("Invalid view conditions", view);
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h1 = cmsCIECAM02Init (0, &vc);
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h2 = cmsCIECAM02Init (0, &vc);
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cmsCIECAM02Forward (h1, &xyz1, &jch1);
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cmsCIECAM02Forward (h2, &xyz2, &jch2);
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cmsCIECAM02Done (h1);
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cmsCIECAM02Done (h2);
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/* Now have colors in JCh, need to calculate J'a'b'
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M = C * F_L^0.25
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J' = 1.7 J / (1 + 0.007 J)
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M' = 43.86 ln(1 + 0.0228 M)
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a' = M' cos(h)
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b' = M' sin(h)
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where
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F_L = 0.2 k^4 (5 L_A) + 0.1 (1 - k^4)^2 (5 L_A)^(1/3),
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k = 1/(5 L_A + 1)
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*/
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k = 1.0 / (1.0 + (5.0 * vc.La));
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k4 = k * k * k * k;
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FL = vc.La * k4 + 0.1 * (1 - k4) * (1 - k4) * cbrt (5.0 * vc.La);
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Mp1 = 43.86 * log (1.0 + 0.0228 * (jch1.C * sqrt (sqrt (FL))));
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Mp2 = 43.86 * log (1.0 + 0.0228 * (jch2.C * sqrt (sqrt (FL))));
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Jp1 = 1.7 * jch1.J / (1.0 + (0.007 * jch1.J));
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Jp2 = 1.7 * jch2.J / (1.0 + (0.007 * jch2.J));
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ap1 = Mp1 * cos (deg2rad (jch1.h));
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ap2 = Mp2 * cos (deg2rad (jch2.h));
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bp1 = Mp1 * sin (deg2rad (jch1.h));
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bp2 = Mp2 * sin (deg2rad (jch2.h));
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return make_float (sqrt ((Jp2 - Jp1) * (Jp2 - Jp1) +
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(ap2 - ap1) * (ap2 - ap1) +
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(bp2 - bp1) * (bp2 - bp1)));
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}
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DEFUN ("lcms-temp->white-point", Flcms_temp_to_white_point, Slcms_temp_to_white_point, 1, 1, 0,
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doc: /* Return XYZ black body chromaticity from TEMPERATURE given in K.
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Valid range of TEMPERATURE is from 4000K to 25000K. */)
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(Lisp_Object temperature)
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{
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cmsFloat64Number tempK;
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cmsCIExyY whitepoint;
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cmsCIEXYZ wp;
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#ifdef WINDOWSNT
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if (!lcms_initialized)
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lcms_initialized = init_lcms_functions ();
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if (!lcms_initialized)
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{
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message1 ("lcms2 library not found");
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return Qnil;
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}
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#endif
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CHECK_NUMBER_OR_FLOAT (temperature);
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tempK = XFLOATINT (temperature);
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if (!(cmsWhitePointFromTemp (&whitepoint, tempK)))
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signal_error("Invalid temperature", temperature);
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cmsxyY2XYZ (&wp, &whitepoint);
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return list3 (make_float (wp.X), make_float (wp.Y), make_float (wp.Z));
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}
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DEFUN ("lcms2-available-p", Flcms2_available_p, Slcms2_available_p, 0, 0, 0,
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doc: /* Return t if lcms2 color calculations are available in this instance of Emacs. */)
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(void)
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{
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#ifdef WINDOWSNT
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Lisp_Object found = Fassq (Qlcms2, Vlibrary_cache);
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if (CONSP (found))
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return XCDR (found);
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else
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{
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Lisp_Object status;
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lcms_initialized = init_lcms_functions ();
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status = lcms_initialized ? Qt : Qnil;
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Vlibrary_cache = Fcons (Fcons (Qlcms2, status), Vlibrary_cache);
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return status;
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}
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#else /* !WINDOWSNT */
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return Qt;
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#endif
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}
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/* Initialization */
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void
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syms_of_lcms2 (void)
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{
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defsubr (&Slcms_cie_de2000);
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defsubr (&Slcms_cam02_ucs);
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defsubr (&Slcms2_available_p);
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defsubr (&Slcms_temp_to_white_point);
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Fprovide (intern_c_string ("lcms2"), Qnil);
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}
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#endif /* HAVE_LCMS2 */
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