Differences

This shows you the differences between two versions of the page.

--- isp:luminance [2023/09/05 05:53] – Igor Yefmov
+++ isp:luminance [2023/09/06 00:34] (current) – [BT. 709] Igor Yefmov
@@ Line 1: / Line 1: @@
 ====== Luma ======
-Luminance of a pixel (read more on [[https://en.wikipedia.org/wiki/Luma_(video)|Wikipeia]]) is a measure of perceived brightness and is calculated in SUB2r code using the following formula:
+===== BT. 709 =====
+Luminance of a pixel (read more on [[https://en.wikipedia.org/wiki/Rec._709|Wikipeia]]) is a measure of perceived brightness and is calculated in SUB2r code using the following formula:
 \[
@@ Line 6: / Line 8: @@
 \]
-This is in accordance with the BT.709 recommendation (and not the "expected" CCIR 601) and the UVC descriptors for USB video transmission reflect that choice.
+This is in accordance with the HDTV's BT.709 recommendation (and not the "expected" CCIR 601) and the UVC descriptors for USB video transmission reflect that choice.
+===== BT. 601 =====
+A.k.a. [[https://en.wikipedia.org/wiki/Rec._601|CCIR 601]]
+If we were to chose the CCIR 601, which is used in most digital standard definitions, the coefficients would be:
+\[
+ luma = 0.299R + 0.587G + 0.114B
+\]
+===== BT. 2020 =====
+According to [[https://en.wikipedia.org/wiki/Rec._2020|Wikipedia]] the new standard's coefficients are yet different still:
+\[
+ luma = 0.2627R + 0.678G + 0.0593B
+\]