[CREATE] W3C Compositing and Blending 1.0 draft is up: implications for OpenRaster?

[Guillermo Espertino (Gez)]

El 09/11/12 14:39, Andrew Chadwick escribió:
> The W3C's new Compositing and Blending working draft[1] was published
> back in August[2], and is being actively maintained. I like it a lot.
> It's very clear about the model SVG and Canvas should use, and
> describes very neatly all the algorithms. In my opinion as a humble
> developer it's much easier to work from than the older SVG Compositing
> Specification[3]. The new spec
>
>   1. Distinguishes firmly between blending and compositing. The older
> draft did not.
>   2. Formally adds four non-separable blend modes: hue, saturation,
> color, luminosity.
>   3. Allows any blend mode to be used with any Porter-Duff compositing operation.
>   4. Describes how isolated groups combine internally and externally.
Andrew:
I'm not an expert about this, but having seen the differences between 
layer blending/compositing in linear space and gamma corrected spaces I 
wonder if this specifications take color management in consideration or 
simply assume the sRGB TRC for the inputs.
Perhaps this question is out of place and it doesn't have anything to do 
with this specification, but when I asked Pippin about why not doing 
always compositing in linear space in GIMP and just ditch the legacy 
blending in gamma-corrected space, one of the reasons he offered was 
that compositing in web browsers is done in non-linear space and designs 
for the web with linear blending would look different than the actual 
rendering in a browser.
That's of course a good reason, but it looks like the way web browsers 
do compositing is keeping us in legacyland.

Since blending in linear space seems mandatory for high quality 
compositing and painting, free software applications should use it.

I did a quick search looking for gamma/linear compositing in w3c but I 
couldn't find anything that suggests that other than sRGB is used.
Was this issue ever discussed?

Kind regards,
Gez.