X-Git-Url: http://users.mur.at/ms/git/gitweb/?p=OpenColorIO-Configs.git;a=blobdiff_plain;f=iif%2Fluts%2Fadx_cid_to_rle.py;fp=iif%2Fluts%2Fadx_cid_to_rle.py;h=c226d4fd2de7670fbbe301e7a4bda1eae5863eca;hp=0000000000000000000000000000000000000000;hb=b7513eb747ab6e0c0937bd4266ed92c14b522acf;hpb=3b239e6199813ed31dc3323c45bc235dbbf7cae3

diff --git a/iif/luts/adx_cid_to_rle.py b/iif/luts/adx_cid_to_rle.py
new file mode 100755
index 0000000..c226d4f
--- /dev/null
+++ b/iif/luts/adx_cid_to_rle.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+
+import math, numpy
+
+"""
+
+const float REF_PT = (7120.0 - 1520.0) / 8000.0 * (100.0 / 55.0) - log10(0.18);
+
+const float LUT_1D[11][2] = {
+	{-0.190000000000000, -6.000000000000000},
+	{ 0.010000000000000, -2.721718645000000},
+	{ 0.028000000000000, -2.521718645000000},
+	{ 0.054000000000000, -2.321718645000000},
+	{ 0.095000000000000, -2.121718645000000},
+	{ 0.145000000000000, -1.921718645000000},
+	{ 0.220000000000000, -1.721718645000000},
+	{ 0.300000000000000, -1.521718645000000},
+	{ 0.400000000000000, -1.321718645000000},
+	{ 0.500000000000000, -1.121718645000000},
+	{ 0.600000000000000, -0.926545676714876}
+};
+
+	// Convert Channel Independent Density values to Relative Log Exposure values
+	float logE[3];
+	if ( cid[0] <= 0.6) logE[0] = interpolate1D( LUT_1D, cid[0]);
+	if ( cid[1] <= 0.6) logE[1] = interpolate1D( LUT_1D, cid[1]);
+	if ( cid[2] <= 0.6) logE[2] = interpolate1D( LUT_1D, cid[2]);
+
+	if ( cid[0] > 0.6) logE[0] = ( 100.0 / 55.0) * cid[0] - REF_PT;
+	if ( cid[1] > 0.6) logE[1] = ( 100.0 / 55.0) * cid[1] - REF_PT;
+	if ( cid[2] > 0.6) logE[2] = ( 100.0 / 55.0) * cid[2] - REF_PT;
+"""
+
+
+def interpolate1D(x, xp, fp):
+    return numpy.interp(x, xp, fp)
+
+LUT_1D_xp = [-0.190000000000000, 
+              0.010000000000000,
+              0.028000000000000,
+              0.054000000000000,
+              0.095000000000000,
+              0.145000000000000,
+              0.220000000000000,
+              0.300000000000000,
+              0.400000000000000,
+              0.500000000000000,
+              0.600000000000000]
+
+LUT_1D_fp = [-6.000000000000000, 
+             -2.721718645000000,
+             -2.521718645000000,
+             -2.321718645000000,
+             -2.121718645000000,
+             -1.921718645000000,
+             -1.721718645000000,
+             -1.521718645000000,
+             -1.321718645000000,
+             -1.121718645000000,
+             -0.926545676714876]
+
+REF_PT = (7120.0 - 1520.0) / 8000.0 * (100.0 / 55.0) - math.log(0.18, 10.0)
+
+def cid_to_rle(x):
+    if x <= 0.6:
+        return interpolate1D(x, LUT_1D_xp, LUT_1D_fp)
+    return (100.0 / 55.0) * x - REF_PT
+
+def WriteSPI1D(filename, fromMin, fromMax, data):
+    f = file(filename,'w')
+    f.write("Version 1\n")
+    f.write("From %s %s\n" % (fromMin, fromMax))
+    f.write("Length %d\n" % len(data))
+    f.write("Components 1\n")
+    f.write("{\n")
+    for value in data:
+        f.write("        %s\n" % value)
+    f.write("}\n")
+    f.close()
+
+def Fit(value, fromMin, fromMax, toMin, toMax):
+    if fromMin == fromMax:
+        raise ValueError("fromMin == fromMax")
+    return (value - fromMin) / (fromMax - fromMin) * (toMax - toMin) + toMin
+
+NUM_SAMPLES = 2**12
+RANGE = (-0.19, 3.0)
+data = []
+for i in xrange(NUM_SAMPLES):
+    x = i/(NUM_SAMPLES-1.0)
+    x = Fit(x, 0.0, 1.0, RANGE[0], RANGE[1])
+    data.append(cid_to_rle(x))
+
+WriteSPI1D('adx_cid_to_rle.spi1d', RANGE[0], RANGE[1], data)
+