[GravityWell]

Not sure what the objective is, but using the "before" example 475kb lena pic, a subsequent jpg at 61k looks very close to the original, and much better than the 61k blurred png.

There is a reason why jpg has survived the test of time. It delivers a good balance of quality, performance, and is well supported. Challengers like JPEG 2000 have not gained much traction because jpg gets the job done. http://en.wikipedia.org/wiki/JPEG_2000

[pornel]

JPEG is very good indeed, but it can't compete when transparency is needed.

I've chosen Lenna as an example image because it's a classic, rather than as an example where lossy PNG can't be beaten.

But take any transparent image from Apple.com, and you can halve its size: http://imgur.com/a/VLlqG

(and images from pngquant2 are even smaller, but there are few that become too lossy).

[graue]

This should be in your article! :) It motivates the technique much better.

[homosaur]

JPEG has no transparency support, for one

[adrianN]

I thought the main reason why JPEG2000 was not widely adopted is its problematic patent status.