Re: [Openexr-devel] 8 bit int?

[Pavel Ledin]

I suggest it too.

In current time it's common limitation of exr format (because it can't
replace tiff format in post production).
So users just need replacement for 8bit TIFF. Because most textures
are still in 8 bit.



Wednesday, June 24, 2009, 1:11:36 AM, you wrote:

> I know this has been covered a couple time over the years, but from my
> cursory search of the archives, not lately, and not to my full 
> satisfaction. :-)

> Is anybody entertaining the idea of adding a uint8 data type to OpenEXR?
>   Sometimes (actually quite frequently) we store things in textures that
> do not need fp16 precision.

> Objections I've seen in previous discussion:

> "It's bad to store luminance" -> We store textures of things like masks
> or linear parameter values that are not luminance and 256 levels are 
> more than enough.

"Use TIFF or PNG" ->> But it's so much nicer to have all our textures in 
> one format, and there is anecdotal evidence (which I'm trying to 
> confirm) that libIlmImf is just flat-out faster to read texture than 
> libtiff (though that's hard to verify with few useful data formats in 
> common between TIFF and OpenEXR).

> "Use fp16 with piz, it compresses as well as 8 bit" -> on disk, maybe,
> but it takes up twice the space in an in-memory tile cache.

> I know you want to avoid a proliferation of data types.  I'm just 
> talking about adding the one type that is by far the most common for 
> source images.

> Anything changed in your philosophy about this since the last time it 
> came up?



-- 
Best regards,
 Pavel Ledin aka Puppet                            mailto:address@hidden
 TD, Trehmer
 Moscow, Russia