diff options
Diffstat (limited to 'src/lcms.c')
| -rw-r--r-- | src/lcms.c | 107 |
1 files changed, 84 insertions, 23 deletions
diff --git a/src/lcms.c b/src/lcms.c index f543a030399..a5e527911ef 100644 --- a/src/lcms.c +++ b/src/lcms.c @@ -139,6 +139,26 @@ chroma, and hue, respectively. The parameters each default to 1. */) return make_float (cmsCIE2000DeltaE (&Lab1, &Lab2, Kl, Kc, Kh)); } +static double +deg2rad (double degrees) +{ + return M_PI * degrees / 180.0; +} + +static cmsCIEXYZ illuminant_d65 = { .X = 95.0455, .Y = 100.0, .Z = 108.8753 }; + +static void +default_viewing_conditions (const cmsCIEXYZ *wp, cmsViewingConditions *vc) +{ + vc->whitePoint.X = wp->X; + vc->whitePoint.Y = wp->Y; + vc->whitePoint.Z = wp->Z; + vc->Yb = 20; + vc->La = 100; + vc->surround = AVG_SURROUND; + vc->D_value = 1.0; +} + /* FIXME: code duplication */ static bool @@ -160,11 +180,62 @@ parse_xyz_list (Lisp_Object xyz_list, cmsCIEXYZ *color) return true; } -DEFUN ("lcms-cam02-ucs", Flcms_cam02_ucs, Slcms_cam02_ucs, 2, 3, 0, +static bool +parse_viewing_conditions (Lisp_Object view, const cmsCIEXYZ *wp, + cmsViewingConditions *vc) +{ +#define PARSE_VIEW_CONDITION_FLOAT(field) \ + if (CONSP (view) && NUMBERP (XCAR (view))) \ + { \ + vc->field = XFLOATINT (XCAR (view)); \ + view = XCDR (view); \ + } \ + else \ + return false; +#define PARSE_VIEW_CONDITION_INT(field) \ + if (CONSP (view) && NATNUMP (XCAR (view))) \ + { \ + CHECK_RANGED_INTEGER (XCAR (view), 1, 4); \ + vc->field = XINT (XCAR (view)); \ + view = XCDR (view); \ + } \ + else \ + return false; + + PARSE_VIEW_CONDITION_FLOAT (Yb); + PARSE_VIEW_CONDITION_FLOAT (La); + PARSE_VIEW_CONDITION_INT (surround); + PARSE_VIEW_CONDITION_FLOAT (D_value); + + if (! NILP (view)) + return false; + + vc->whitePoint.X = wp->X; + vc->whitePoint.Y = wp->Y; + vc->whitePoint.Z = wp->Z; + return true; +} + +/* References: + Li, Luo et al. "The CRI-CAM02UCS colour rendering index." COLOR research + and application, 37 No.3, 2012. + Luo et al. "Uniform colour spaces based on CIECAM02 colour appearance + model." COLOR research and application, 31 No.4, 2006. */ + +DEFUN ("lcms-cam02-ucs", Flcms_cam02_ucs, Slcms_cam02_ucs, 2, 4, 0, doc: /* Compute CAM02-UCS metric distance between COLOR1 and COLOR2. -Each color is a list of XYZ coordinates, with Y scaled about unity. -Optional argument is the XYZ white point, which defaults to illuminant D65. */) - (Lisp_Object color1, Lisp_Object color2, Lisp_Object whitepoint) +Each color is a list of XYZ tristimulus values, with Y scaled about unity. +Optional argument WHITEPOINT is the XYZ white point, which defaults to +illuminant D65. +Optional argument VIEW is a list containing the viewing conditions, and +is of the form (YB LA SURROUND DVALUE) where SURROUND corresponds to + 1 AVG_SURROUND + 2 DIM_SURROUND + 3 DARK_SURROUND + 4 CUTSHEET_SURROUND +The default viewing conditions are (20 100 1 1). */) + (Lisp_Object color1, Lisp_Object color2, Lisp_Object whitepoint, + Lisp_Object view) { cmsViewingConditions vc; cmsJCh jch1, jch2; @@ -188,17 +259,13 @@ Optional argument is the XYZ white point, which defaults to illuminant D65. */) if (!(CONSP (color2) && parse_xyz_list (color2, &xyz2))) signal_error ("Invalid color", color2); if (NILP (whitepoint)) - parse_xyz_list (Vlcms_d65_xyz, &xyzw); + xyzw = illuminant_d65; else if (!(CONSP (whitepoint) && parse_xyz_list (whitepoint, &xyzw))) signal_error ("Invalid white point", whitepoint); - - vc.whitePoint.X = xyzw.X; - vc.whitePoint.Y = xyzw.Y; - vc.whitePoint.Z = xyzw.Z; - vc.Yb = 20; - vc.La = 100; - vc.surround = AVG_SURROUND; - vc.D_value = 1.0; + if (NILP (view)) + default_viewing_conditions (&xyzw, &vc); + else if (!(CONSP (view) && parse_viewing_conditions (view, &xyzw, &vc))) + signal_error ("Invalid view conditions", view); h1 = cmsCIECAM02Init (0, &vc); h2 = cmsCIECAM02Init (0, &vc); @@ -227,10 +294,10 @@ Optional argument is the XYZ white point, which defaults to illuminant D65. */) Mp2 = 43.86 * log (1.0 + 0.0228 * (jch2.C * sqrt (sqrt (FL)))); Jp1 = 1.7 * jch1.J / (1.0 + (0.007 * jch1.J)); Jp2 = 1.7 * jch2.J / (1.0 + (0.007 * jch2.J)); - ap1 = Mp1 * cos (jch1.h); - ap2 = Mp2 * cos (jch2.h); - bp1 = Mp1 * sin (jch1.h); - bp2 = Mp2 * sin (jch2.h); + ap1 = Mp1 * cos (deg2rad (jch1.h)); + ap2 = Mp2 * cos (deg2rad (jch2.h)); + bp1 = Mp1 * sin (deg2rad (jch1.h)); + bp2 = Mp2 * sin (deg2rad (jch2.h)); return make_float (sqrt ((Jp2 - Jp1) * (Jp2 - Jp1) + (ap2 - ap1) * (ap2 - ap1) + @@ -291,12 +358,6 @@ DEFUN ("lcms2-available-p", Flcms2_available_p, Slcms2_available_p, 0, 0, 0, void syms_of_lcms2 (void) { - DEFVAR_LISP ("lcms-d65-xyz", Vlcms_d65_xyz, - doc: /* D65 illuminant as a CIE XYZ triple. */); - Vlcms_d65_xyz = list3 (make_float (0.950455), - make_float (1.0), - make_float (1.088753)); - defsubr (&Slcms_cie_de2000); defsubr (&Slcms_cam02_ucs); defsubr (&Slcms2_available_p); |