JPEGmini Shrinks Photos’ File Sizes Online, Without Reducing Quality

shemwhistler

Thought this might be of interest to some;

http://lifehacker.com/5837556/jpegmini-shrinks-photos-file-sizes-online-without-reducing-quality

oshead

It's very good, pity there isn't a stand alone app though.

shemwhistler

oshead wrote: »

It's very good, pity there isn't a stand alone app though.

I was wondering about that, my guess is they want to keep whatever voodoo they're using hidden on their servers, rather than give out the secret source code.

oshead

or maybe they are looking to licence the technology to the big online photo websites like flickr etc...

AnCatDubh

But, hold on a minute.....

JPG is already a highly compressed format so if you are to go from a size as the screen shot says of 2200k to 750k, then you have to be loosing something? No?

Like RAW to JPG in the first place?

From the screen shot of the article on lifehacker, to my eyes and non calibrated display, it looks as if there is less contrast - the after JPEGmini shot looks quite washed out.

Even if my suspicions have any validity, I think it still sound like a handy/nifty wee tool to have.

DaireQuinlan

AnCatDubh wrote: »

But, hold on a minute.....

JPG is already a highly compressed format so if you are to go from a size as the screen shot says of 2200k to 750k, then you have to be loosing something? No?

Like RAW to JPG in the first place?

From the screen shot of the article on lifehacker, to my eyes and non calibrated display, it looks as if there is less contrast - the after JPEGmini shot looks quite washed out.

Even if my suspicions have any validity, I think it still sound like a handy/nifty wee tool to have.

It actually uses the same encoding mechanism as JPEG (as it has to, given that it produces a spec-compliant JPEG file), but they claim to have some super smarty way of deciding which bits of the image to compress more heavily than others. It also works better with larger files apparently (according to the slightly more detailed techcrunch article I read about it). T&Cs on the site are worth a read though if you're concerned about these things, they reserve the right to use your image for promotional purposes etc etc, which seems a bit of a steep price to pay for eking another few KB out of your compressed file.

Also, dude. It's 'lose', not 'loose'. I never thought I'd see the day

AnCatDubh

Actually, a good explanation of what is happening here:

http://www.jpegmini.com/main/technology

A lot of talk about perceptive and human visual perception. Thus where they are getting their bang from is probably at a technical level not distinguishable to the human eye.

Also ran an image through it and the quality is way better than the lifehacker example shown. from 1.2Mb to about 250k. Nice one.

Only issue for them maybe their market in that storage becomes ever cheaper albeit none the easier to manage.

AnCatDubh

DaireQuinlan wrote: »

Also, dude. It's 'lose', not 'loose'. I never thought I'd see the day

shemwhistler

For anyone that's interest I've done a wee test here;

http://www.flickr.com/photos/mattjeanes/sets/72157627498739727/

And to be honest, to my untrained eye, I can't see a difference.


I was thinking about uses for this, and yes with HDD space being dirt cheap, I think I'd always keep a higher quality image at home. I can see it's value being in mobile web usage.

All these mobile devices; tablets, phones etc are likely running off a 3g network, and with the carriers beginning to get rid of unlimited data plans, the ability to send higher quality images to those devices with little discernible lack in quality is extremely valuable.

As has already been said, if they license this to any platform that uploads pictures, Flickr, Picassa, wordpress etc, could be pretty huge.

Edit: Not sure why I didn't think of this first;


Original by Matt Jeanes, on Flickr


Processed by Matt Jeanes, on Flickr

DaireQuinlan

AnCatDubh wrote: »

Only issue for them maybe their market in that storage becomes ever cheaper albeit none the easier to manage.

Mobile devices. Probably the biggest growth area in the technology sphere at the moment, and one in which both storage capacity (on the devices) and the cost of bandwidth are both big issues again.

DaireQuinlan

shemwhistler wrote: »

For anyone that's interest I've done a wee test here;

And to be honest, to my untrained eye, I can't see a difference.


I was thinking about uses for this, and yes with HDD space being dirt cheap, I think I'd always keep a higher quality image at home. I can see it's value being in mobile web usage.

All these mobile devices; tablets, phones etc are likely running off a 3g network, and with the carriers beginning to get rid of unlimited data plans, the ability to send higher quality images to those devices with little discernible lack in quality is extremely valuable.

As has already been said, if they license this to any platform that uploads pictures, Flickr, Picassa, wordpress etc, could be pretty huge.

r

It's kinda hard to tell, as that image is pretty soft all over, but if you pixel peep enough you can kind of tell that some of the high-frequency image information is being lost. For all practical purposes I'd say you wouldn't notice it. It'd be interesting to see it done on a sharp image though.

shemwhistler

Apologies, I'm not entirely sure what you mean by soft and sharp, so I racked my brain for what I considered to be the sharpest image I had on flickr, and came up with this. I hope it's of more use.

http://www.flickr.com/photos/mattjeanes/sets/72157627498739727/with/6127171534/


Lego - Original by Matt Jeanes, on Flickr


Lego - Processed by Matt Jeanes, on Flickr

hbr

shemwhistler wrote: »

Apologies, I'm not entirely sure what you mean by soft and sharp, so I racked my brain for what I considered to be the sharpest image I had on flickr, and came up with this. I hope it's of more use.

Rescaled images (smaller than the original) are heavily sharpened on flickr
and most other photo sharing sites. It would be better to compare a couple
of 100% crops.

shemwhistler

hbr wrote: »

Rescaled images (smaller than the original) are heavily sharpened on flickr
and most other photo sharing sites. It would be better to compare a couple
of 100% crops.

Sorry, you've completely lost me with 100% crops.

I'll get me coat.

DaireQuinlan

hbr wrote: »

Rescaled images (smaller than the original) are heavily sharpened on flickr
and most other photo sharing sites. It would be better to compare a couple
of 100% crops.

The originals are available of the above, if you click through the (rather annoying) all sizes thing that flickr have.

hbr

DaireQuinlan wrote: »

The originals are available of the above, if you click through the (rather annoying) all sizes thing that flickr have.

That should be a valid comparison. Looking at the original and processed versions,
I can see some differences in contrast and noise. I tried using Gimp to re-compress
the original to approximately the same size as the JPEGmini. The result looks a bit noisier than the JPEGmini version.

The original is at the top, JPEGmini middle and Gimp bottom.

shemwhistler

hbr wrote: »

That should be a valid comparison. Looking at the original and processed versions,
I can see some differences in contrast and noise. I tried using Gimp to re-compress
the original to approximately the same size as the JPEGmini. The result looks a bit noisier than the JPEGmini version.

The original is at the top, JPEGmini middle and Gimp bottom.

Hi hbr, I'm only getting a broken link, is it me or you?

hbr

shemwhistler wrote: »

Hi hbr, I'm only getting a broken link, is it me or you?

It was displaying ok here, but that may be because it is in my browser cache.
The file seemed to be missing so I have uploaded it again. Is it ok now?

shemwhistler

hbr wrote: »

It was displaying ok here, but that may be because it is in my browser cache.
The file seemed to be missing so I have uploaded it again. Is it ok now?

Working now thanks.

I'm curious to hear your assessment, my eye is rubbish, the mini'd one seems pretty good, maybe a bit lighter, and as you say, less noise than the gimp'd version.

5uspect

Perhaps overlay them in Photoshop and change the blend mode to difference.
I'll make up a test image later and try myself.

EDIT:
Okay so here's a quick test.
I made up this test image:


Nothing special, just a few sharp lines and come colour gradients.
Saved it as a jpeg in PS at quality 10 resulting in a 260KB file.

Ran it through JPEGmini and got a 152KB file.
Saved the original again in PS at quality 4 and got a 144KB file.

Then to compare I overlaid both the heavily compressed images over the original lightly compressed JPEG and changed the blend mode to difference. There was no immediate difference and a black image resulted. I had to rescale the histogram to bring out the small differences.

As you can see here for JPEG mini


and the resaved image:


These are pretty tiny differences that you have to go looking for. Both methods seem to give very similar results so I would say form this quick, crude, test you're probably better off just compressing in PS once.
Would be good to look at some real world examples too.