Initial import of argyll version 1.5.1-8debian/1.5.1-8

1 files changed, 226 insertions, 0 deletions

diff --git a/icc/testDE2K.c b/icc/testDE2K.c
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+
+/* Test the CIE delta E 2000 code */
+
+#include <stdio.h>
+#include <math.h>
+#include "icc.h"
+
+
+/* Reference data */
+
+#define NTESTS 34
+
+/* From the Sharma, Wu and Dalal "Implementation Notes" etc. paper: */
+struct {
+	double Lab1[3];
+	double Lab2[3];
+	double de;
+} ref[NTESTS] = {
+	{ 50.0000, 2.6772, -79.7751, 50.0000, 0.0000, -82.7485, 2.0425 },
+	{ 50.0000, 3.1571, -77.2803, 50.0000, 0.0000, -82.7485, 2.8615 },
+	{ 50.0000, 2.8361, -74.0200, 50.0000, 0.0000, -82.7485, 3.4412 },
+	{ 50.0000, -1.3802, -84.2814, 50.0000, 0.0000, -82.7485, 1.0000 },
+	{ 50.0000, -1.1848, -84.8006, 50.0000, 0.0000, -82.7485, 1.0000 },
+	{ 50.0000, -0.9009, -85.5211, 50.0000, 0.0000, -82.7485, 1.0000 },
+	{ 50.0000, 0.0000, 0.0000, 50.0000, -1.0000, 2.0000, 2.3669 },
+	{ 50.0000, -1.0000, 2.0000, 50.0000, 0.0000, 0.0000, 2.3669 },
+	{ 50.0000, 2.4900, -0.0010, 50.0000, -2.4900, 0.0009, 7.1792 },
+	{ 50.0000, 2.4900, -0.0010, 50.0000, -2.4900, 0.0010, 7.1792 },
+	{ 50.0000, 2.4900, -0.0010, 50.0000, -2.4900, 0.0011, 7.2195 },
+	{ 50.0000, 2.4900, -0.0010, 50.0000, -2.4900, 0.0012, 7.2195 },
+	{ 50.0000, -0.0010, 2.4900, 50.0000, 0.0009, -2.4900, 4.8045 },
+	{ 50.0000, -0.0010, 2.4900, 50.0000, 0.0010, -2.4900, 4.8045 },
+	{ 50.0000, -0.0010, 2.4900, 50.0000, 0.0011, -2.4900, 4.7461 },
+	{ 50.0000, 2.5000, 0.0000, 50.0000, 0.0000, -2.5000, 4.3065 },
+	{ 50.0000, 2.5000, 0.0000, 73.0000, 25.0000, -18.0000, 27.1492 },
+	{ 50.0000, 2.5000, 0.0000, 61.0000, -5.0000, 29.0000, 22.8977 },
+	{ 50.0000, 2.5000, 0.0000, 56.0000, -27.0000, -3.0000, 31.9030 },
+	{ 50.0000, 2.5000, 0.0000, 58.0000, 24.0000, 15.0000, 19.4535 },
+	{ 50.0000, 2.5000, 0.0000, 50.0000, 3.1736, 0.5854, 1.0000 },
+	{ 50.0000, 2.5000, 0.0000, 50.0000, 3.2972, 0.0000, 1.0000 },
+	{ 50.0000, 2.5000, 0.0000, 50.0000, 1.8634, 0.5757, 1.0000 },
+	{ 50.0000, 2.5000, 0.0000, 50.0000, 3.2592, 0.3350, 1.0000 },
+	{ 60.2574, -34.0099, 36.2677, 60.4626, -34.1751, 39.4387, 1.2644 },
+	{ 63.0109, -31.0961, -5.8663, 62.8187, -29.7946, -4.0864, 1.2630 },
+	{ 61.2901, 3.7196, -5.3901, 61.4292, 2.2480, -4.9620, 1.8731 },
+	{ 35.0831, -44.1164, 3.7933, 35.0232, -40.0716, 1.5901, 1.8645 },
+	{ 22.7233, 20.0904, -46.6940, 23.0331, 14.9730, -42.5619, 2.0373 },
+	{ 36.4612, 47.8580, 18.3852, 36.2715, 50.5065, 21.2231, 1.4146 },
+	{ 90.8027, -2.0831, 1.4410, 91.1528, -1.6435, 0.0447, 1.4441 },
+	{ 90.9257, -0.5406, -0.9208, 88.6381, -0.8985, -0.7239, 1.5381 },
+	{ 6.7747, -0.2908, -2.4247, 5.8714, -0.0985, -2.2286, 0.6377 },
+	{ 2.0776, 0.0795, -1.1350, 0.9033, -0.0636, -0.5514, 0.9082 }
+};
+
+double icmCIE2K(double *Lab1, double *Lab2);
+
+int main(void) {
+	int rv = 0;
+	int i;
+
+	printf("Starting Test:\n");
+
+#ifdef NEVER
+	for (i = 0; i < NTESTS; i++) {
+		printf("Lab1 = %f %f %f\n", ref[i].Lab1[0], ref[i].Lab1[1], ref[i].Lab1[2]);
+		printf("Lab2 = %f %f %f\n", ref[i].Lab2[0], ref[i].Lab2[1], ref[i].Lab2[2]);
+		printf("de = %f\n",ref[i].de);
+	}
+#endif
+
+	/* Test it all out */
+	for (i = 0; i < NTESTS; i++) {
+		double de;
+
+		de = icmCIE2K(ref[i].Lab1, ref[i].Lab2);
+		if (fabs(de - ref[i].de) > 0.0001) {
+			printf("Error at index %d:\n",i);
+			printf("Lab1 = %f %f %f\n", ref[i].Lab1[0], ref[i].Lab1[1], ref[i].Lab1[2]);
+			printf("Lab2 = %f %f %f\n", ref[i].Lab2[0], ref[i].Lab2[1], ref[i].Lab2[2]);
+			printf("DeltaE is %f, should be %f\n\n",de,ref[i].de);
+			rv = 1;
+		}
+		de = icmCIE2K(ref[i].Lab2, ref[i].Lab1);
+		if (fabs(de - ref[i].de) > 0.0001) {
+			printf("Error at index %d:\n",i);
+			printf("Lab1 = %f %f %f\n", ref[i].Lab2[0], ref[i].Lab2[1], ref[i].Lab2[2]);
+			printf("Lab2 = %f %f %f\n", ref[i].Lab1[0], ref[i].Lab1[1], ref[i].Lab1[2]);
+			printf("DeltaE is %f, should be %f\n\n",de,ref[i].de);
+			rv = 1;
+		}
+	}
+
+	printf("Test Finished\n");
+	return rv;
+}
+
+#ifdef NEVER		/* Test implementation in icc.c */
+
+/* From the paper "The CIEDE2000 Color-Difference Formula: Implementation Notes, */
+/* Supplementary Test Data, and Mathematical Observations", by */
+/* Gaurav Sharma, Wencheng Wu and Edul N. Dalal, */
+/* Color Res. Appl., vol. 30, no. 1, pp. 21-30, Feb. 2005. */
+
+/* Return the CIEDE2000 Delta E color difference measure squared, for two Lab values */
+double icmCIE2Ksq(double *Lab0, double *Lab1) {
+	double C1, C2;
+	double h1, h2;
+	double dL, dC, dH;
+	double dsq;
+
+	/* The trucated value of PI is needed to ensure that the */
+	/* test cases pass, as one of them lies on the edge of */
+	/* a mathematical discontinuity. The precision is still */
+	/* enough for any practical use. */
+#define RAD2DEG(xx) (180.0/3.14159265358979 * (xx))
+#define DEG2RAD(xx) (3.14159265358979/180.0 * (xx))
+
+	/* Compute Cromanance and Hue angles */
+	{
+		double C1ab, C2ab;
+		double Cab, Cab7, G;
+		double a1, a2;
+
+		C1ab = sqrt(Lab0[1] * Lab0[1] + Lab0[2] * Lab0[2]);
+		C2ab = sqrt(Lab1[1] * Lab1[1] + Lab1[2] * Lab1[2]);
+		Cab = 0.5 * (C1ab + C2ab);
+		Cab7 = pow(Cab,7.0);
+		G = 0.5 * (1.0 - sqrt(Cab7/(Cab7 + 6103515625.0)));
+		a1 = (1.0 + G) * Lab0[1];
+		a2 = (1.0 + G) * Lab1[1];
+		C1 = sqrt(a1 * a1 + Lab0[2] * Lab0[2]);
+		C2 = sqrt(a2 * a2 + Lab1[2] * Lab1[2]);
+
+		if (C1 < 1e-9)
+			h1 = 0.0;
+		else {
+			h1 = RAD2DEG(atan2(Lab0[2], a1));
+			if (h1 < 0.0)
+				h1 += 360.0;
+		}
+
+		if (C2 < 1e-9)
+			h2 = 0.0;
+		else {
+			h2 = RAD2DEG(atan2(Lab1[2], a2));
+			if (h2 < 0.0)
+				h2 += 360.0;
+		}
+	}
+
+	/* Compute delta L, C and H */
+	{
+		double dh;
+
+		dL = Lab1[0] - Lab0[0];
+		dC = C2 - C1;
+		if (C1 < 1e-9 || C2 < 1e-9) {
+			dh = 0.0;
+		} else {
+			dh = h2 - h1;
+			if (dh > 180.0)
+				dh -= 360.0;
+			else if (dh < -180.0)
+				dh += 360.0;
+		}
+
+		dH = 2.0 * sqrt(C1 * C2) * sin(DEG2RAD(0.5 * dh));
+	}
+
+	{
+		double L, C, h, T;
+		double hh, ddeg;
+		double C7, RC, L50sq, SL, SC, SH, RT;
+		double dLsq, dCsq, dHsq, RCH;
+
+		L = 0.5 * (Lab0[0]  + Lab1[0]);
+		C = 0.5 * (C1 + C2);
+		if (C1 < 1e-9 || C2 < 1e-9) {
+			h = h1 + h2;
+		} else {
+			h = h1 + h2;
+			if (fabs(h1 - h2) > 180.0) {
+				if (h < 360.0)
+					h += 360.0;
+				else if (h >= 360.0)
+					h -= 360.0;
+			}
+			h *= 0.5;
+		}
+		T = 1.0 - 0.17 * cos(DEG2RAD(h-30.0)) + 0.24 * cos(DEG2RAD(2.0 * h))
+		  + 0.32 * cos(DEG2RAD(3.0 * h + 6.0)) - 0.2 * cos(DEG2RAD(4.0 * h - 63.0));
+		hh = (h - 275.0)/25.0;
+		ddeg = 30.0 * exp(-hh * hh);
+		C7 = pow(C,7.0);
+		RC = 2.0 * sqrt(C7/(C7 + 6103515625.0));
+		L50sq = (L - 50.0) * (L - 50.0);
+		SL = 1.0 + (0.015 * L50sq)/sqrt(20.0 + L50sq);
+		SC = 1.0 + 0.045 * C;
+		SH = 1.0 + 0.015 * C * T;
+		RT = -sin(DEG2RAD(2 * ddeg)) * RC;
+
+		dLsq = dL/SL;
+		dCsq = dC/SC;
+		dHsq = dH/SH;
+
+		RCH = RT * dCsq * dHsq;
+
+		dLsq *= dLsq;
+		dCsq *= dCsq;
+		dHsq *= dHsq;
+
+		dsq = dLsq + dCsq + dHsq + RCH;
+	}
+
+	return dsq;
+
+#undef RAD2DEG
+#undef DEG2RAD
+}
+
+/* Return the CIE2DE000 Delta E color difference measure for two Lab values */
+double icmCIE2K(double *Lab0, double *Lab1) {
+	return sqrt(icmCIE2Ksq(Lab0, Lab1));
+}
+
+#endif /* NEVER */