W3C home > Mailing lists > Public > www-svg@w3.org > February 2011

Re: SVG masks and luminance calculations

From: Erik Dahlstrom <ed@opera.com>
Date: Thu, 03 Feb 2011 09:37:41 +0100
To: www-svg@w3.org, "Robert Longson" <longsonr@gmail.com>
Message-ID: <op.vqbjk0xjgeuyw5@localhost>
On Thu, 03 Feb 2011 08:22:00 +0100, Robert Longson <longsonr@gmail.com>  
wrote:

>> I don't fully understand why masks need this kind of special treatment,  
>> if
>> one wants a linearRGB colorspace why not just use
>> color-interpolation="linearRGB" explicitly? The color-interpolation
>> property has an initial value of 'sRGB', and it applies to container
>> elements (including <mask>). To me this looks like a contradiction in  
>> the
>> spec. For performance reasons I would like to propose that the default
>> behaviour is changed so that it respects the 'color-interpolation'
>> property, while maintaining the existing behaviour via
>> "color-interpolation=linearRGB".
>
> Erik,
>
> Is that what Opera currently implements? If not what is it doing?

Like I wrote in [1] my current thinking is that the linearRGB luminance  
calculation for the mask element is in conflict with the  
'color-interpolation' property.

Opera is currently doing the luminance calculation in sRGB-space.  
According to the mozilla bugreport comments (see link in [1]) that's also  
what e.g Photoshop does.

Cheers
/Erik

[1] http://www.w3.org/mid/op.vp95kmojgeuyw5@localhost

-- 
Erik Dahlstrom, Core Technology Developer, Opera Software
Co-Chair, W3C SVG Working Group
Personal blog: http://my.opera.com/macdev_ed
Received on Thursday, 3 February 2011 08:38:17 GMT

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