Guetzli JPEG Encoder

[AndZyk]

This may be of interest for anybody seeking for ways to compress images.

Google open sourced a new JPEG encoder „Guetzli“ (catchy name):

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Guetzli is a JPEG encoder that aims for excellent compression density at high visual quality. Guetzli-generated images are typically 20-30% smaller than images of equivalent quality generated by libjpeg. Guetzli generates only sequential (nonprogressive) JPEGs due to faster decompression speeds they offer.

Announcement
GitHub repository

I am not quite sure, how this new JPEG encoder could be used except with the command line. Maybe some apps (f. e. ImageOptim) will implement it in their interfaces or maybe it could be used with an module?

Haven't even tried it out yet and it sounds performance intensive, but I am glad that they sticked with JPEG and didn't introduced another exotic format.

Regards, Andreas

[matjazp]

https://github.com/processwire/processwire-issues/issues/191 

Yes, it use large amount of RAM and it's slooooow. I tried on windows, 5 MB jpg, peak memory usage was around 4 GB, CPU usage was 25% and it took 10-15 minutes (not seconds) to finish, src 6.020.543 bytes, dst 4.343.674 bytes.

[AndZyk]

Thank you for the hint. Nice to see, that it is already in discussion.

Wow, I didn't thought that this encoder needs so much performance. 

[AndZyk]

I had some time now to try out Guetzli and have to say, that it is really memory hungry.  But the results on the other hand are impressive too. I made some tests with good old Lenna:

Uncompressed (312.31 kb)

Compressed with JPEGOptim and Jpegtran (ImageOptim default) (291.87 kb)

Compressed with Guetzli (127.8 kb)

From 312 kb to 127 kb is indeed impressive.

For anyone who doesn't like the command line. The newest alpha of ImageOptim 1.7.1a4 also includes Guetzli, but there it is disabled by default and you will be warned, if you activate it. 

[Christophe]

Try with TinyJPG...

NB: posting the images on the Forums compresses them, doesn't it?
PS: I use more TinyPNG than TinyJPG.

Edited March 27, 2017 by Christophe

[FrancisChung]

Out of interest, how much would the TinyJPG compressed image be ?

[AndZyk]

13 hours ago, Christophe said:

Try with TinyJPG...

You mean the web service tinyjpg.com? Never heard of it before.

7 minutes ago, FrancisChung said:

Out of interest, how much would the TinyJPG compressed image be ?

Compressed with TinyJPG (87 kb)

But I think this web service is using lossy compression. At least I couldn't find a clear statement on their website. So this web service is out of question for me, because I am only looking for loseless ways to compress images. But I might be wrong.

13 hours ago, Christophe said:

NB: posting the images on the Forums compresses them, doesn't it?

I don't think so. Looking into the developer tools, I see no difference to my original images.

Here an interesting post about tests with Guetzli: https://www.34sp.com/blog/speed-testing-googles-guetzli-jpeg-encoder/

[FrancisChung]

Wow quick reply!

If only Guetzil was as speedy and compact like your response, @AndZyk

 

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Here an interesting post about tests with Guetzli: https://www.34sp.com/blog/spe

That post was ace. Thanks.

[szabesz]

15 hours ago, AndZyk said:

because I am only looking for loseless ways to compress images

Where did you read that Guetzil is lossless?

https://arxiv.org/abs/1703.04421

"visually indistinguishable images" also "...by combining advanced psychovisual models with lossy compression techniques."

It is lossy, so if you want to keep the original, you need to keep the original

Edited March 28, 2017 by szabesz
typo

[AndZyk]

1 hour ago, szabesz said:

It is lossy, so if you want to keep the original, you need to keep the original

Ok, so it is lossy. But my point was, that in comparison to TinyJPG it doesn't visually alter the image with darker colors and blur.

[matjazp]

PNG Optimization Tools Overview: https://css-ig.net/png-tools-overview 

[szabesz]

I've just noticed that they added Guetzli to the ImageOptim Mac app:

https://imageoptim.com/changelog.html

I tested it with small images and indeed it is slooow. However, I as far as I can see with my ow eyes, turning on Guetzli generates about the same "virtual" quality as ImageOptim does without it (when we get about the same kilobytes), except that using Guetzli takes much longer. I cannot see any improvements here. Maybe it is because of the images used, I dunno. I will keep on trying but currently I missed to experience the revolution...

[AndZyk]

Thank you for mentioning. I have mentioned earlier in this thread, that Guetzli is in the newest alpha of ImageOptim included, but forgot to spread the news that it is now in the stable version as well.

I am using Guetzli with ImageOptim for a while now and yes it is really slow and if you dare to optimize a lot of high quality images, be ready to get your fan heated up. 

But on the other hand I usually have a optimization rate of about 60%. Compared to the about 20% when Guetzli is disabled, I think it is absolutely worth it.