Re: [whatwg] Canvas and color colorspaces (was: WebGL and ImageBitmaps)

On Sat, Apr 30, 2016 at 12:38 PM, Kornel <kornel@geekhood.net> wrote:

>
> > On 30 Apr 2016, at 19:07, Rik Cabanier <cabanier@gmail.com> wrote:
> >
> > It would be ideal if we can specify that the canvas backing store is in
> the device profile.
>
> How would the website know what profile this is? If it's just a boolean
> setting, then I don't see how it would make it possible to use such canvas
> correctly, e.g. convert a XYZ color to canvas' color space.
>

This is how content is drawn today. A website doesn't know what profile a
browser is using.
Introducing this would make canvas drawing match HTML which is what the
spec is intending and users want.


> Is device profile exposed somewhere in the platform yet? If not, I think
> it'd be better to leave it hidden to avoid adding more fingerprinting
> vectors.
>

I'm unsure how this would contribute to fingerprinting.
If browser start following the spec wrt icc profile conversion, you could
infer the profile by drawing an image and looking at the pixels.


> Setting the canvas to a website-supplied profile seems OK to me. It'd mean
> the website already knows how to convert colors to the given colorspace,
> and the same profile could be passed back by toDataURL().
>

That would indeed be the ideal solution. My worry is that it introduces a
lot of changes in the browser (ie see Justin's email that started this
thread) and I'd like to see a solution sooner than later.

Received on Saturday, 30 April 2016 20:20:07 UTC