[Bf-committers] Cinepaint & high definition color support

[Stephane SOPPERA]

Ton Roosendaal wrote:

> Hi all,
>
> At the Siggraph Blender BOF we also had a discussion with the  
> maintainer of CinePaint (formerly filmgimp). He mentioned that he was  
> developing a generic library to work with arbitrary depth color buffers:
>
> http://cinepaint.bigasterisk.com/ImgImgArchitecture
>
> Having Blender reading/writing high definition color buffers is a 
> long  wanted feature, but it has some implications... especially with 
> all  Blender internals and the Imbuf library being defaulted 
> (hardcoded) to  4x8 bits.
>
> However, as a first step I can code an option that retains the (hi 
> def)  render buffer Blender already uses. This is 4x16 bits for 
> normal  render, and 4x32 for unified. This then can not only be used 
> for  gamma/brightness/contrast adjusting, but also exported using the  
> CinePaint lib.
>
> Reading back such files, and use it for textures we can then can 
> still  postpone, until we find the solution for how to integrate this 
> in the  current image/texture code in Blender.
>
> A) would that satisfy?

Is the 4x32 unified color buffer an HDR (High Dynamic Range) one? I mean
can colors in this buffer be greater than 1 (assuming 1 is white)? That
could be interesting to have an HDR image buffer (maybe is it called a
floating point image buffer) to have correct motion blur and glow on
highlights or when facing a halo light. It can also be interesting to
change exposition after rendering, without needing to render again.

Another interesting feature would be to be able to write sequence
plug-ins using HDR images.

Support for HRD images (with colors greater than 1) will also be very
interesting for:
- reflection textures
- combined with Ambient Occlusion, can't that be used to do image based
lighting?

Thanks for your work,

-- 
Stephane SOPPERA
http://perso.wanadoo.fr/stephane.soppera