Transparent JPEGs for the browser

jim.studt.net

6 pointsjws3 comments

Why send men to the moon? Because its a challenge a way to test yourself and to test conventional thought.

You cut your image sizes almost in half. If you are a mega busy site or a catalog or similar you save bandwidth and reduce connection time to your site.

So why would you go through all this trouble?

For photographic style images, a JPEG+mask is about half the size of a PNG, much less for very large images. You could just manage your images and masks as separate images, but that carries the cost of an extra GET and possibly misplacing one part.

In my case I have a large number of masked, photographic images which need to be in the 300ppi range to manage on a single page and the GETs and file size savings are a clear win.

Note: The canvas method works in Firefox, but not for everyone. I'll have to find an afflicted version and see what is wrong. IE should work with FlashCanvas, but I don't have an IE to test with and fear I left something important out of the example at http://blog.jackadam.net/2010/alpha-jpegs/

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