I'm a big fan of Yahoo's recommendations for speeding up websites. One of the recommendations is to combine images where possible to cut down on size and the number of requests. However, I've noticed that while it can be easy to use CSS sprites for layouts, other image uses aren't as easily combined. The primary example I'm thinking of is a blog or article list, where each blog or article also has an image associated with it. Those images can greatly affect load time and page size, especially if they aren't optimized. What I'm looking for, in concept or in practice, is a way to dynamically combine those images while running them through a loss-less compression using PHP.
A few added thoughts or concerns:
Combining the images and generating
a dynamic CSS stylesheet to position
the backgrounds of the images might
be one way to go about it, but I
also worry about accessibility and
semantics. As far as I understand,
CSS images should be used for layout
elements and the img tag (with the
alt attribute) should be used for
images that are meant to convey
information. I could set the image
as a background to a div element and
substitute a title attribute for the
alt attribute, but I'm unsure about
the accessibility and semantic
implications of doing so.
Might the GD library be a good
candidate for something like this?
Can you recommend other options?
posted date: 2008-12-17 08:30:00