- From: Bjartur Thorlacius <svartman95@gmail.com>
- Date: Mon, 13 Feb 2012 10:33:07 +0000
On 2/13/12, Gray Zhang <otakustay at gmail.com> wrote: > We would like to present an authoring difficulty with regard to showing > images on the Web with limited bandwidth, when deferring loading of certain > or all images are preferable. We have some vague ideas about what > browser/markup solutions instead of script solutions might look like, but > we are more interested in having the problems solved. > Scenario > > 1. On a product description page of a shopping site, there are several > *main* pictures of the product, along with about twenty or so camera > pictures of the product taken from different angles. When the HTML is > parsed, browsers by default simultaneously start downloading all images, > potentially making some of the *main* ones invisible. Hmm. So you request a way to declare which images are important, and wich are not? > 2. On an album page where hundreds of pictures are expected to be shown, > it is often required that pictures currently in a user's screen should > appear as fast as possible. Loading of a picture outside the screen can > be > deferred to the time that the picture enters or is about to enter the > screen, for the purpose of optimization user experience. This seems like something interactive user agents should implement. > 3. For a site with limited bandwidth on the server side, it is > preferable to minimize the amount of data transferred per each page view. > 70% of the users only read the first screen and hence pictures outside > the > first screen don't need to be downloaded before the user starts to scroll > the page. This is to reduce server-side cost. > > 1. the @defer attribute on <img> and <iframe> > 2. the similar @deferpolicy attribute with value a combination of > visible, > network-idle and render-idle > 3. a global switch as a http header or an attribute on html to switch > UAs image loading from "obtain images immediately" to "obtain on demand" > or > vice versa. Would this not depend equally on factors such as whether the user agent would download the images over a metered connection?
Received on Monday, 13 February 2012 02:33:07 UTC