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Re: [css3-images] Units for `image-resolution: from-image`

From: Simon Sapin <simon.sapin@exyr.org>
Date: Wed, 23 Apr 2014 15:38:21 +0100
Message-ID: <5357D05D.20904@exyr.org>
To: fantasai <fantasai.lists@inkedblade.net>, www-style@w3.org
On 17/04/2014 19:09, fantasai wrote:
> On 07/26/2013 09:59 AM, Tab Atkins Jr. wrote:
>> While that's reasonable, still, if you know the size of a "real inch",
>> then you know the ratio of a real inch to a CSS in.  This can be used
>> to interpret the format-specified ratio in a more accurate way than
>> just assuming that it's referring to a CSS in.
>> What I'm saying is, I prefer to leave this underdefined.
> I disagree. I think the concept of "inch" should be consistent
> throughout all of CSS if possible. So <length>, media queries,
> and image-resolution.

Yes, the "in" and "dpi" units should be consistent within CSS. But 
neither of them is related to the imperial inch unit.

> In other news, if the image says "I'm 72dpi" and I write
>     image-resolution: 72dpi
> these should both give the same result.

I disagree. I’m pretty sure that "inch" in EXIF refers to the imperial 
unit rather than the CSS "in" unit that is worth 96 times 0.0213 degrees 
of visual angle.

Simon Sapin
Received on Wednesday, 23 April 2014 14:38:45 UTC

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