Re: -webkit-image-set

Great points everyone. Seems you've thought this out a bit better. 

KS


On Friday, March 23, 2012 at 4:25 PM, Phil Archer wrote:

> 
> 
> On 23/03/2012 20:11, Ariel wrote:
> > 
> > I disagree. The position of the image is presentation, but that actual
> > content - meaning how many pixels are in the image is content.
> > 
> > The visual size is presentation, but the actual physical number of
> > pixels is content.
> > 
> > There are two issues here: Changing the layout depending on screen size
> > - that belongs in css certainly.
> > 
> > But selecting which image, with the only difference being the dpi does
> > not belong in css, that should be supported in html.
> > 
> 
> 
> +1
> 
> I was giving a talk on this only yesterday [1] and it's in the Mobile 
> Web Best Practices for a reason - resizing images takes processing power 
> and causes a re-flow of the page (more processing power). So yes, height 
> and width dimensions must be sent with the image in the markup and they 
> must match the intrinsic size of the image.
> 
> The the method suggested of basically defining as group of images and 
> using media queries to tell the browser which one - and one only - to 
> download - sounds spot on to me and I very much hope that that, or 
> something very like it, is what we end up with. The kind of hack I put 
> together looks ugly [2] (it uses PHP and the GD library to resize images 
> on the server). OK, it works and it means you only have to have one copy 
> of the image on your server but it really doesn't feel right and I'd 
> like it to be unnecessary. It's a lot better than resizing in the 
> browser though!
> 
> Phil.
> 
> [1] http://www.w3.org/2012/Talks/0322_phila_openMIC/
> [2] http://philarcher.org/diary/2011/phpimageadaptation/
> 
> > 
> > -Ariel
> > 
> > On Fri, 23 Mar 2012, Kevin Suttle wrote:
> > 
> > > This is a point I brought up on the site. To re-cap:
> > > 
> > > "img is content, so having it in markup makes sense. However, the size
> > > of an img is presentational. By design, this is most likely a problem
> > > that CSS needs to solve."
> > > 
> > > I guess the way I see it, if it is the same image content, does it
> > > need a markup-based solution? We're trying to tackle a
> > > performance/presentation issue. Thoughts?
> > > 
> > > KS
> > > 
> > > 
> > > On Friday, March 23, 2012 at 3:56 AM, Dominique Hazael-Massieux wrote:
> > > 
> > > > WebKit has just integrated a patch (from Apple) to make it possible to
> > > > provide variants of a CSS image based on the device scale factor:
> > > > http://trac.webkit.org/changeset/111637
> > > > 
> > > > I don't think that addresses the markup-based use case, but it probably
> > > > should inform it.
> > > > 
> > > > Dom
> 
> -- 
> 
> 
> Phil Archer
> W3C eGovernment
> http://www.w3.org/egov/
> 
> http://philarcher.org
> +44 (0)7887 767755
> @philarcher1
> 
>