[Radiance-general] Animation Exposure

[Peter Apian-Bennewitz]

Rob Guglielmetti wrote:

>
> On Jan 30, 2004, at 6:04 PM, Mark de la Fuente wrote:
>
>> edious task to accomplish with rview.  I guess I can interpolate
>> and guesstimate, but perhaps there is a better way of doing this?
>> Anyone run into this issue before?
>
>
> Hi Mark,
>
> Check out phisto (http://radsite.lbl.gov/radiance/man_html/phisto_1.htm).
>
> This will help, as will using the -h parameter of pcond (there's an 
> example on the phisto manpage).
>
> Cheers.
>
> =================
>    Rob Guglielmetti
> www.rumblestrip.org
>
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>
>
phisto seems to be one useful tool in the process, but the interesting 
part may be the semi-automatic, yet smooth, expose "drift". It's 
probably hard to do fully automatic, as a "good" exposure depends on the 
part of the image you are interested in. I had glanced a bit at the 
problem in May 2001 (the http://www.pab-opto.de/pers/animation/hist1.mpg 
animation shows the histogram overlaid on the image), but haven't found 
a generally nice method.
Personally I was surprised that my digital Nikon handles automatic 
exposures quite well, apparently a lot of engineering has gone into an 
intelligent guess as to what is imporant in an image. Similar algorithms 
plus (spline-based ?) interpolation may be very useful for automatic 
exposure settings in Radiance animations.
cheers
Peter

-- 
 pab-opto, Freiburg, Germany, http://www.pab-opto.de