X-Git-Url: http://users.mur.at/ms/git/gitweb/?p=OpenColorIO-Configs.git;a=blobdiff_plain;f=aces_0.1.1%2Fluts%2Fsony%2Fslog2.py;fp=aces_0.1.1%2Fluts%2Fsony%2Fslog2.py;h=858def5c1ddd7c92244a4169bb345c0899a3926b;hp=0000000000000000000000000000000000000000;hb=9ce48d45f92a12b20b39eddd527b3c392b6a87cd;hpb=2335988b9d3ecc6b0d4f6f76938e1eaae449cac2

diff --git a/aces_0.1.1/luts/sony/slog2.py b/aces_0.1.1/luts/sony/slog2.py
new file mode 100755
index 0000000..858def5
--- /dev/null
+++ b/aces_0.1.1/luts/sony/slog2.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+
+import math
+
+# IT's annoying that the 1023,4 and 4095,16 almost, but dont exactly, cancel. UGH
+# The intent is clearly to have the same mapping, but it's not done very well.
+# Sony engineers and/or the Academy should pick one of these mappings for both.
+
+def SLog_to_lin(x):
+    return (math.pow(10.0,(((((x*1023.0)/4.0-16.0)/219.0)-0.616596-0.03)/0.432699))-0.037584)*0.9
+
+def Fit(value, fromMin, fromMax, toMin, toMax):
+    if fromMin == fromMax:
+        raise ValueError("fromMin == fromMax")
+    return (value - fromMin) / (fromMax - fromMin) * (toMax - toMin) + toMin
+
+def SLog2_to_lin(x):
+    x = Fit(x, 64.0/1023.0, 940.0/1023.0, 0.0, 1.0)
+    if x < 0.030001222851889303:
+        y = ((x-0.030001222851889303 ) * 0.28258064516129)
+    else:
+        y = (219.0*(math.pow(10.0, ((x-0.616596-0.03)/0.432699)) - 0.037584) /155.0)
+    return y*0.9
+    
+"""
+steps = 1024
+for i in xrange(steps):
+    x = i/(steps-1.0)
+    print x, SLog2_to_lin(x)
+"""
+"""
+print SLog2_to_lin_copy(90.0/1023.0) / 0.9
+print SLog2_to_lin_copy(91.0/1023.0) / 0.9
+print SLog2_to_lin_copy(582.0/1023.0) / 0.9
+print SLog2_to_lin_copy(940.0/1023.0) / 0.9
+print SLog2_to_lin_copy(998.0/1023.0) / 0.9
+"""
+
+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()
+
+NUM_SAMPLES = 2**14
+RANGE = (-0.125, 1.125)
+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(SLog2_to_lin(x))
+WriteSPI1D('sony_slog2_10.spi1d', RANGE[0], RANGE[1], data)