[whatwg] Implementation complexity with elements vs an attribute (responsive images)

[Kornel Lesiński]

On Sun, 13 May 2012 23:00:10 +0100, Bjartur Thorlacius  
<svartman95 at gmail.com> wrote:

> I've got a hunch I'm over-thinking this, but might
> bandwidth-constrained users not prefer miniatures instead of huge
> pixelated images?

Perhaps sometimes, but support for this would tie layout and bandwidth  
together, and that complicates things. It's easier for authors if images  
don't unexpectedly change displayed size.

I think we can assume that authors won't provide image in resolution that  
is too low to be useful, so huge pixelation may not be a problem.

Authors can decrease image filesize not only by decreasing pixel size, but  
also by using lossy image compression (lower JPEG quality, less colors in  
PNG/GIF files).



For pure bandwidth optimisation on 100dpi displays (rather than avoiding  
sending too large 200dpi images to users with 100dpi displays) an explicit  
filesize information may be the solution:

<img srcset="q95percent.jpg size=100KB, q30percent.jpg size=20KB">

then UA can easily make decision how much bandwidth it can use (e.g. aim  
to download any page in 5 seconds, so try to get image sizes to add up to  
less than 5*network B/s).

-- 
regards, Kornel Lesiński