[whatwg] <img srcset> for responsive bitmapped content images
mjs at apple.com
Thu May 10 13:18:41 PDT 2012
On May 10, 2012, at 6:47 AM, Simon Pieters <simonp at opera.com> wrote:
> On Thu, 10 May 2012 15:24:28 +0200, Tab Atkins Jr. <jackalmage at gmail.com> wrote:
>> For two, I'm not sure that it's particularly obvious that when you say
>> "2x", you should make sure your image was saved as 196dpi. You have
>> to already know what the default resolution is. As well, I think that
>> values like 300dpi are pretty common, and they don't map to integral
>> 'x' values. If people say "screw it" and use "3x", this'll be
>> slightly wrong and I think will cause ugly blurring. If we make this
>> take <resolution>, people can just use the dpi unit.
> Can we just use CSS's 'dpi' instead?
> <img src="default.jpg" srcset="highres.jpg 300dpi">
CSS's 'dpi' is confusing, because it actually defines the ratio of device pixels to CSS inches, not device pixels to physical inches, as most users would expect 'dpi' to mean in the context of a graphics program. So 300dpi would mean the same thing as 3.125x, and would likely itself result in ugly blurring, since scaling by a fractional scale factor rarely looks crisp.
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