Daniel Matthews wrote:
>
> I call it contrast masking, or dynamic range compression.

Yes, I forgot to mention dynamic range compression :)


> The subject matter was shot in full sunlight and included white marble and
> black granite so you can imagine how massive the dynamic range was!

There is a company that has developed a CCD camera with automatic
dynamic range compression. It has an LCD element in front of the
CCD wich gets it's control voltage from the CCD. The more light
a pixel receives the darker the corresponding LCD pixel gets. They'd
love to use a scene like this for their demo.

 
> I think your patch will be very useful in some scenes.

I have studied transfer curves of Kodak films and some of the
slide films seem to match the simple exponential function.
I think this has wider use than just for the really hard cases.
Some people prefer to do all the tweaking within povray so I'll
add a gain keyword which will help to adjust scenes with lower
contrast ratios. assumed_gamma works as a contrast control when
combined with compression so that should cover the basics.

Of course it will be harder to develop scenes when adjusting
1 or 2 new variables so not many will try. It will most likely
not make an existing scene look better.

 
_____________
Kari Kivisalo

Post a reply to this message