
The importance of rendering intent,
and the consequent requirement
for different exponents for
encoding (yE) and decoding (yD),
has been poorly recognized and
poorly documented in the develop-
ment of video.
Eq 23.1
YE =0"5;YD =2.5;
yE.YD
= 1.25
As I explained in
Rendering intent,
on page 81, it is
important for perceptual reasons to alter the tone scale
of an image reproduced at a luminance substantially
lower than that of the original scene, reproduced with
limited contrast ratio, or viewed in a dim surround. The
dim surround condition is characteristic of television
viewing. In video, the alteration ...