jpsdr
11th April 2018, 20:51
Reading the REC-BT.2087, i've discovered the M2 step.
This explain, why, even if EOTF is identical (which first made me think it was possible to just make linear matrix conversion), if white point is identical, as the coordinates of reference R,G,B are differents, you can't avoid the EOTF/OETF non linear part.
If you read REC-BT.601, EOTF is identical, and even if reference R,G,B is not exactly the same than REC-BT.709, they are so close than conversion can be made directly.
Now, what i'm curious about are these famous M2 matrix !
If anyone know how from the coordinates of reference R,G,B (and probably also the white point), you can get these matrix coefficients, i am very interested.
:thanks:
Edit :
Maybe finaly found something here (http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html).
This explain, why, even if EOTF is identical (which first made me think it was possible to just make linear matrix conversion), if white point is identical, as the coordinates of reference R,G,B are differents, you can't avoid the EOTF/OETF non linear part.
If you read REC-BT.601, EOTF is identical, and even if reference R,G,B is not exactly the same than REC-BT.709, they are so close than conversion can be made directly.
Now, what i'm curious about are these famous M2 matrix !
If anyone know how from the coordinates of reference R,G,B (and probably also the white point), you can get these matrix coefficients, i am very interested.
:thanks:
Edit :
Maybe finaly found something here (http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html).