[webkit-dev] Double-Resolution (Retina) Images - Re: -webkit-image-set

[Evan Martin]

On Wed, Apr 25, 2012 at 3:22 AM, Kenneth Rohde Christiansen
<kenneth.christiansen at gmail.com> wrote:
> So the original iPhone has a dpi of 163, but it reported a CSS dpi of
> 96? meaning that in screen width it had around 3,3 CSS inches where as
> the physical inches are more close to 1.96.
>
> Why is this? Because the original iPhone reported an unchanged dpi of
> 96 even though it was in reality 163 and now everyone are depending on
> that?

CSS defines one inch = 96px, because doing otherwise broke content
(even pre-iOS content).
http://www.w3.org/TR/css3-values/#absolute-lengths