Christian Walther <cwa### [at] gmxch> wrote:

>
> 8-bit sampling (256 different intensity values) is too coarse for
> linear samples, you'll clearly see color banding in the dark areas if
> you display such a file correctly...

Yes, I've been reading about that on other websites. Anywhere from 12-bit up
to 14-bit seems to be required. BTW, If you haven't already done so, I
would strongly recommend taking a look at the following (more or less
definitive) website about this, and the gamma question in general...

http://www.poynton.com/notes/Timo/Concerning_Timo.html
and fish around for Poynton's other pages as well, especially his GAMMA FAQ.
 A very knowledgable fellow.
>
> o you need to use a file format that stores the gamma value (only PNG at
> this time) and a viewer application that honors this value and
> transforms the values read from the file from gamma-1.0-encoded to
> gamma-2.0-encoded before sending them to video memory. (Unfortunately
> most applications don't do that.)

Right. That's why  I don't use the .png file format for my output files.  On
both of my relatively older computers (a PowerMac and  Pentium II) I don't
seem to have ANY applications (other than POV itself) that recognizes the
gamma info embedded into it, not even the two different versions of
Photoshop I have (v4 and v5). So I use the standard PC .bmp format--not
only out of necessity, but also because the more I read about applications
treating .png "oddly," the less inclined I am to use it.

Before commenting further, a quick question: What computer
system are you running POV on?  Seems like an arcane question, I know. I'm
running v3.6.1 on 32-bit Windows.

Ken

Post a reply to this message