diff --git a/index.html b/index.html
index 6b10132..89d6253 100644
--- a/index.html
+++ b/index.html
@@ -711,6 +711,12 @@ Terms, definitions, and abbreviated terms
vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a
phosphorescent screen.
+ Electro-Optical Transfer Function
+
+ EOTF
+
+ The transfer function between the electrical or digital domain and light energy. It defines the amount of light emitted by a display for a given input signal.
+
Least Significant Byte
LSB
@@ -724,6 +730,12 @@ Terms, definitions, and abbreviated terms
Most significant byte of a multi-byte value.
+
+ Opto-Electrical Transfer Function
+
+ OETF
+
+ The transfer function between light energy and the electrical or digital domain. It defines the amount of light in a scene required to produce a given output signal.
@@ -3725,6 +3737,17 @@ cICP Coding-independent code points for video sig
PNG format, it should be noted that this format is not part of the [[ITU-R-BT.709]] standard.
+
If Video Full Range Flag is 0
+ (a narrow-range image), recommended practice
+ is to define transfer functions
+ such as EOTF or inverse OETF
+ over the extended range,
+ so as to include negative values.
+ This is done as follows:
+
+
+ out = sign(in) * TransferFunction(abs(in))
+
The cICP chunk MUST come before the PLTE and IDAT chunks.