Re: [css4-color] color-correction

On Thu, Apr 18, 2013 at 12:16 AM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:

> On Wed, Apr 17, 2013 at 7:39 PM, Rik Cabanier <cabanier@gmail.com> wrote:
> > In this morning telecon, Chris objected to this new property.
> > The minutes are not very detailed so I would like to know what the
> problem
> > is with this new property.
> >
> > My reason for asking is that this property is very similar how Adobe
> treats
> > colors in its authoring applications and acrobat.
>
> Chris can probably fill in better, but I believe his argument was
> that, at the time color-correction was first proposed (years ago)
> several popular formats were *not* color-managed.  In particular,
> Flash wasn't.  Today, Flash can be color-managed, as can JPEG and
> other image formats.  Thus, if an author wants to ensure everything
> matches, they just need to opt everything into color management, and
> they're done.  No need to involve CSS.


That doesn't make sense. How would they opt everything in?

Today if an author uses images and CSS colors and wants that to look the
same everywhere, it can't be done (ie clothing, furniture, color swatches,
etc) since the color values are sent straight to the display.
I believe IE will colormanage images with embedded profiles so an author
could use that to get the "correct" color but that still won't match what
the author saw on his screen.

As an aside, you don't want to honor embedded profiles in images by
default. InDesign ignores them because of we got many customer complaints.

Thinking about this some more, I propose 3 values for color-correction:

   1. 'off': send CSS colors, images and video straight to the screen. ICC
   profiles are ignored
   2. 'deviceRGB': send CSS colors, images and video straight to the
   screen. However, if there is tagged content, transform its colors to the
   device's colorspace.
   3. 'sRGB': assume everything is in sRGB and convert from sRGB colors to
   the device's colorspace. This implies that tagged content will go from its
   original color to sRGB and then to the final colorspace

option 1 is the current behavior (except IE)
option 2 is IE's behavior. Tagged images will display as good as possible
for your display.
option 3 allows an author full color management  The page should look the
same on any device (as long as it can reach sRGB's gamut)