On Mon, 14 May 2012 01:30:20 +0100, Odin Hørthe Omdal <[email protected]>
wrote:
All optional replacements of the src will have to be fitted in the same
box as the original src. That might actually require you to specify both
width and height upfront. Of course, people won't really do that, so I
guess we're bound to get differing behaviour... Hm.
What do people think about that? What happens here? You have no info on
the real size of the picture. I guess maybe the browser should never
load any srcset alternatives then? If you have no information at all
it's rather hard to make a judgement.
A photo gallery wants to show you a fullscreen picture, and give you:
<img src=2048px.jpg srcset="4096px.jpg 2x">
In this example, us (humans :P) can easily see that one is 2048 px and
the other 4096 px. If I'm viewing this on my highres Nokia N9, a naïve
implementation could pick the 2x, because it knows that's nicely highres
just like its own screen.
But it would actually be wrong! It would never need anything else than
the 2048 px for normal viewing because it is anyway exceeding its real
pixels on the screen.
If srcset/<picture> provides authors with good way to serve images at most
appropriate size, they won't need to resort to tricks with downsizing
high-res images to smaller size.
For a full-width image on a ~960px viewport (assuming author doesn't have
better sizes available) this would be appropriate:
<img src=2048px.jpg srcset="2048px.jpg 2x, 4096px.jpg 4x"
style="width:100%">
--
regards, Kornel Lesiński
