
Owing to the dependence of the
optimum end-to-end power func-
tion upon viewing conditions,
there here ought to be a user
control for rendering intent-
perhaps even replacing BRIGHTNESS
and CONTRAST- but there isn't!
Figure 24.9
Luma/color
difference flavors
The transfer functions of the decoder (or the CRT) are
intertwined with gamma correction. As I explained on
page 81, an end-to-end power function having an
exponent of about 1.25 is appropriate for typical televi-
sion viewing in a dim surround. The encoder of
Figure 24.7 imposes a 0.5-power function; the decoder
of Figure 24.8 imposes ...