A while back we ran a comparison of PNG, JPG, WebP, and HIPIX looking at the various compression details and artifacts. The results were interesting, with HIPIX emerging as the leader in detail and filesize. However, in the comments someone brought up another format called ‘JPEGMini’, however the entire algorithm is proprietary and locked up so that I couldn’t test it.
That might change now, thanks to the JPEGMini website. Using their website you can upload images or entire albums to be recompressed with their algorithm for an estimated 5x on savings with no perceivable difference in quality. And all for free. The example images they show are impressive, hopefully I can get some time later today to actually run some tests.
Doesn’t look that impressive. Seems to just compress your JPEGs more. I couldn’t see any improvement in quality at all the the same file size. But for someone who always shoots “fine” JPEGs with their digital camera and has no software to turn those into smaller website friendly JPEGs, I can see some value, but there are faster/easier freeware alternatives for this.
I think at a fixed filesize, you’re right there will be no difference.. The “benefits” of JPEGMini is that you should be able to sustain an equal level of quality at a significantly smaller filesize.
But that’s what I’m not seeing. If I send them a 5MB jpg, they send me back a 1MB jpg. But that 1MB jpg looks like what you would get if you recompressed a 5MB jpg down to 1MB using any image processing software. There’s no improvement in quality in the images I’ve tried.
JPEGmini finds the optimal compression level that can be applied to each photo. Keeping it perceptually identical to the source! What you gain is file size. Not every 5MB photo can be compressed to 1MB some can be only compressed by 20% and some by 80%, JPEGmini finds the maximum level of compression you can apply to an image without degrading image quality on the screen or even in fine print!