Progressive JPGs and IE
Stoyan Stefanov from the Exceptional Performance team at Yahoo! published Part 4 of his Image Optimization series on the Yahoo! User Interface (YUI) Blog. He reports on interesting research into the relative optimization characteristics between baseline JPGs and progressive JPGs. It’s interesting to this blog’s readers because he discloses that IE does not render progressive jpgs progressively, instead waiting until the full source is downloaded before displaying the image. Since Mr. Stefanov’s research shows that progressives are often lighter weight than baseline jpgs its probably best to use them regardless of IEs peculiar behavior.