From c07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Mon, 1 Sep 2014 15:43:52 +0200 Subject: Imported Upstream version 1.6.3 --- xicc/cam02.c | 94 +++++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 67 insertions(+), 27 deletions(-) (limited to 'xicc/cam02.c') diff --git a/xicc/cam02.c b/xicc/cam02.c index 1ab6abc..3684a78 100644 --- a/xicc/cam02.c +++ b/xicc/cam02.c @@ -38,6 +38,21 @@ /* with the ICC convention (not 100.0 as assumed by the CIECAM spec.) */ /* Note that all whites are assumed to be normalised (ie. Y = 1.0) */ +/* + TTBD: Should convert to using Timo Kunkel and Erik Reinhard's simplified + and improved version of CIECAM02 (ie. "CIECAM02-KR"). + + The rgbp compression has it's problems in terms of perceptual + uniformity. A color with one component near zero might shift + all the components to -ve values on inverse conversion - ie. + a 1 DE shift in Jab becomes a masive DE in XYZ/Lab/perceptual, + with (say) a darl red becomong black because the blue + value is small. One way around this is to re-introduce + a flag to turn off perfect symetry by disabling + expansion on the reverse conversion. + + */ + /* Various additions and changes have been made to allow the CAM conversions to and from an unbounded range of XYZ and Jab values, @@ -106,6 +121,7 @@ #include "numlib.h" #define ENABLE_COMPR /* [Def] Enable XYZ compression */ +#undef ENABLE_DECOMPR /* [Undef] Enable XYZ de-compression */ #define ENABLE_BLUE_ANGLE_FIX /* [Def] Limit maximum blue angle */ #define ENABLE_DDL /* [Def] Enable k1,k2,k3 overall ss limit values (seems to be the best scheme) */ #undef ENABLE_SS /* [Undef] Disable overall ss limit values (not the scheme used) */ @@ -123,10 +139,10 @@ #undef DISABLE_HHKR /* Debug - disable Helmholtz-Kohlraush */ #ifdef ENABLE_COMPR -# define BC_WHMINY 0.3 /* [0.3] Compression direction minimum Y value */ -# define BC_RANGE_R 0.01 /* [0.01] Set compression range as prop. of distance to neutral - red */ -# define BC_RANGE_G 0.05 /* [0.05] Set compression range as prop. of distance to neutral - green*/ -# define BC_RANGE_B 0.10 /* [0.10] Set compression range as prop. of distance to neutral - blue */ +# define BC_WHMINY 0.2 /* [0.2] Compression direction minimum Y value */ +# define BC_RANGE_R 0.01 /* [0.02] Set comp. range as prop. of distance to neutral - red */ +# define BC_RANGE_G 0.01 /* [0.02] Set comp. range as prop. of distance to neutral - green*/ +# define BC_RANGE_B 0.01 /* [0.02] Set comp. range as prop. of distance to neutral - blue */ # define BC_MAXRANGE 0.13 /* [0.13] Maximum compression range */ # define BC_LIMIT 0.7 /* [0.7] Correction limit (abs. rgbp distance shift) */ #endif /* ENABLE_COMPR */ @@ -174,7 +190,7 @@ double minj = 1e38, maxj = -1e38; static void cam_free(cam02 *s); static int set_view(struct _cam02 *s, ViewingCondition Ev, double Wxyz[3], - double La, double Yb, double Lv, double Yf, double Fxyz[3], + double La, double Yb, double Lv, double Yf, double Yg, double Gxyz[3], int hk); static int XYZ_to_cam(struct _cam02 *s, double *Jab, double *xyz); static int cam_to_XYZ(struct _cam02 *s, double *xyz, double *Jab); @@ -263,7 +279,9 @@ double Yb, /* Relative Luminance of Background to reference white (range 0.0 .. double Lv, /* Luminance of white in the Viewing/Scene/Image field (cd/m^2) */ /* Ignored if Ev is set to other than vc_none */ double Yf, /* Flare as a fraction of the reference white (Y range 0.0 .. 1.0) */ -double Fxyz[3], /* The Flare white coordinates (typically the Ambient color) */ +double Yg, /* Flare as a fraction of the ambient (Y range 0.0 .. 1.0) */ +double Gxyz[3], /* The Glare white coordinates (typically the Ambient color) */ + /* If <= 0 will Wxyz will be used. */ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ ) { double tt, t1, t2; @@ -271,7 +289,8 @@ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ int i; if (Ev == vc_none) { - /* Compute the internal parameters by interpolation */ + /* Compute the internal parameters from the */ + /* ratio of La to Lv by interpolation */ int i; double r, bf; /* Dark, dim, average, above average */ @@ -302,26 +321,32 @@ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ s->F = t_F[i] * (1.0 - bf) + t_F[i+1] * bf; } else { /* Compute the internal parameters by category */ + /* Fake up Lv according to category */ switch(Ev) { case vc_dark: s->C = 0.525; s->Nc = 0.8; s->F = 0.8; + Lv = La/0.033; break; case vc_dim: s->C = 0.59; s->Nc = 0.95; s->F = 0.9; + Lv = La/0.1; + break; + case vc_average: + default: + s->C = 0.69; + s->Nc = 1.0; + s->F = 1.0; + Lv = La/0.2; break; case vc_cut_sheet: s->C = 0.41; s->Nc = 0.8; s->F = 0.8; - break; - default: /* average */ - s->C = 0.69; - s->Nc = 1.0; - s->F = 1.0; + Lv = La/0.02; // ??? break; } } @@ -331,12 +356,21 @@ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ s->Wxyz[0] = Wxyz[0]; s->Wxyz[1] = Wxyz[1]; s->Wxyz[2] = Wxyz[2]; - s->Yb = Yb > 0.005 ? Yb : 0.005; /* Set minimum to avoid divide by 0.0 */ s->La = La; + s->Yb = Yb > 0.005 ? Yb : 0.005; /* Set minimum to avoid divide by 0.0 */ + s->Lv = Lv; s->Yf = Yf; - s->Fxyz[0] = Fxyz[0]; - s->Fxyz[1] = Fxyz[1]; - s->Fxyz[2] = Fxyz[2]; + s->Yg = Yg; + if (Gxyz[0] > 0.0 && Gxyz[1] > 0.0 && Gxyz[2] > 0.0) { + tt = Wxyz[1]/Gxyz[1]; /* Scale to white ref white */ + s->Gxyz[0] = tt * Gxyz[0]; + s->Gxyz[1] = tt * Gxyz[1]; + s->Gxyz[2] = tt * Gxyz[2]; + } else { + s->Gxyz[0] = Wxyz[0]; + s->Gxyz[1] = Wxyz[1]; + s->Gxyz[2] = Wxyz[2]; + } s->hk = hk; /* The rgba vectors */ @@ -365,10 +399,15 @@ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ /* Compute values that only change with viewing parameters */ /* Figure out the Flare contribution to the flareless XYZ input */ - tt = s->Yf * s->Wxyz[1]/s->Fxyz[1]; - s->Fsxyz[0] = tt * s->Fxyz[0]; - s->Fsxyz[1] = tt * s->Fxyz[1]; - s->Fsxyz[2] = tt * s->Fxyz[2]; + s->Fsxyz[0] = s->Yf * s->Wxyz[0]; + s->Fsxyz[1] = s->Yf * s->Wxyz[1]; + s->Fsxyz[2] = s->Yf * s->Wxyz[2]; + + /* Add in the Glare contribution from the ambient */ + tt = s->Yg * s->La/s->Lv; + s->Fsxyz[0] += tt * s->Gxyz[0]; + s->Fsxyz[1] += tt * s->Gxyz[1]; + s->Fsxyz[2] += tt * s->Gxyz[2]; /* Rescale so that the sum of the flare and the input doesn't exceed white */ s->Fsc = s->Wxyz[1]/(s->Fsxyz[1] + s->Wxyz[1]); @@ -522,7 +561,8 @@ int hk /* Flag, NZ to use Helmholtz-Kohlraush effect */ printf("Relative liminance of background Yb = %f\n", s->Yb); printf("Adapting liminance La = %f\n", s->La); printf("Flare Yf = %f\n", s->Yf); - printf("Flare color Fxyz = %f %f %f\n", s->Fxyz[0], s->Fxyz[1], s->Fxyz[2]); + printf("Glare Yg = %f\n", s->Yg); + printf("Glare color Gxyz = %f %f %f\n", s->Gxyz[0], s->Gxyz[1], s->Gxyz[2]); printf("Internal parameters:\n"); printf("Surround Impact C = %f\n", s->C); @@ -569,7 +609,7 @@ double XYZ[3] XYZi[2] = XYZ[2]; #endif - TRACE(("\nForward conversion:\n")) + TRACE(("\nCIECAM02 Forward conversion:\n")) TRACE(("XYZ = %f %f %f\n",XYZ[0], XYZ[1], XYZ[2])) #ifdef DISABLE_MATRIX @@ -622,7 +662,7 @@ double XYZ[3] /* but compressing towards white seems to be the best.) */ icmSub3(cvec, wrgb, rgbp); /* Direction of white target */ - TRACE(("rgbp %f %f %f\n", rgbp[0], rgbp[1], rgbp[2])) + TRACE(("ch %d, rgbp %f %f %f\n", i, rgbp[0], rgbp[1], rgbp[2])) TRACE(("cvec %f %f %f\n", cvec[0], cvec[1], cvec[2])) if (cvec[i] < 1e-9) { /* compression direction can't correct this coord */ @@ -632,7 +672,7 @@ double XYZ[3] /* Scale compression vector to make it move a unit in normal direction */ icmScale3(cvec, cvec, 1.0/cvec[i]); /* Normalized vector to white */ - TRACE(("cvec %f %f %f\n", cvec[0], cvec[1], cvec[2])) + TRACE(("ncvec %f %f %f\n", cvec[0], cvec[1], cvec[2])) /* Compute intersection of correction direction with this limit plane */ /* (This corresponds with finding displacement of rgbp by cvec */ @@ -971,7 +1011,7 @@ double Jab[3] #endif - TRACE(("\nReverse conversion:\n")) + TRACE(("\nCIECAM02 Reverse conversion:\n")) TRACE(("Jab %f %f %f\n",Jab[0], Jab[1], Jab[2])) JJ = Jab[0] * 0.01; /* J/100 */ @@ -1153,7 +1193,7 @@ double Jab[3] #endif -#ifdef ENABLE_COMPR +#ifdef ENABLE_DECOMPR /* Undo soft limiting */ { double tt; /* Temporary */ @@ -1181,7 +1221,7 @@ double Jab[3] /* but compressing towards white seems to be the best.) */ icmSub3(cvec, wrgb, rgbp); /* Direction of white target */ - TRACE(("rgbp %f %f %f\n", rgbp[0], rgbp[1], rgbp[2])) + TRACE(("ch %d, rgbp %f %f %f\n", i, rgbp[0], rgbp[1], rgbp[2])) TRACE(("cvec %f %f %f\n", cvec[0], cvec[1], cvec[2])) if (cvec[i] < 1e-9) { /* compression direction can't correct this coord */ -- cgit v1.2.3