Comments on: More thoughts on automated image optimization for Plone

By: Anthony Gerrard

Anthony Gerrard — Tue, 09 Mar 2010 13:40:40 +0000

We recently had a user upload two bmp files that were 28MB each. I think it would be wise to include bmp file type in your list of image types that can be converted to jpegs. Unfortunately there are users out there who are quite ignorant about image formats, dimensions and compression.

I know it's slightly out of scope but a similar tool to pick up large File objects would be useful for administrators. We'd really like to know if a user has uploaded a 100MB powerpoint.

By: Alec Mitchell

Alec Mitchell — Thu, 04 Mar 2010 19:30:09 +0000

Matt,

Yes, I use ANTIALIAS in PIL transformations, but I’ve had clients for whom the result was not acceptable. ImageMagick is pretty close to state of the art as far as scaling goes and the techniques it uses go far beyond anti-aliasing (See: http://www.imagemagick.org/Usage/resize/). There are comparisons to Photoshop and some anti-aliased scaling output here: http://www.xs4all.nl/~bvdwolf/main/foto/down_sample/example1.htm

It also supports an almost magical “liquid scaling” feature that can change an aspect ratio without significantly distorting the image content.

I wouldn’t suggest making it a dependency for Plone though, because it’s a pain to install. For an add-on that wants to offer quality image transformations, it should be seriously considered, IMHO. Also, if you want to offer flipping/rotation of JPEG images, using libjpeg/jpegtran/jhead allows for extremely fast lossless transforms (whereas both PIL and ImageMagick degrade JPEGs on each transform). See: http://www.imagemagick.org/Usage/formats/#jpg_lossless

By: Geir Bækholt

Geir Bækholt — Wed, 03 Mar 2010 22:42:07 +0000

Yes! This functionality would be very useful, — but the configuation seems a tad technical for control panels.
There is little reason to vary these settings from site to site. I’d be happy to see this happening automatically in the background instead of adding more buttons to tweak.

By: Jon Stahl

Jon Stahl — Wed, 03 Mar 2010 20:35:49 +0000

@Lee, @Cris — awesome! I will think a bit more about how to fold the ideas Matt mentions for the “SuperImageField” into this. I was thinking more from a site admin point of few, not at the individual content creator level, but it would be really great to think at that level as well — thanks!

By: Cris Ewing

Cris Ewing — Wed, 03 Mar 2010 19:59:18 +0000

As the manager of a large website with lots of content contributors and lots of images (we do radiology, folks, images is what we are about) I'd be 100% behind any effort to work on this, especially if we can put some focus on allowing content creators to manage the images they upload when they upload them. I can even see if there might be some funds I can shake loose. This would be a great boon to us and we should pony up to support it if possible.

By: Lee Joramo

Lee Joramo — Wed, 03 Mar 2010 17:48:21 +0000

Jon,
Sounds great. I have several sites that need this badly.
You can put designKiln down for 10% of the project cost up to $500.

By: Jon Stahl

Jon Stahl — Wed, 03 Mar 2010 17:26:09 +0000

@Julian – Great point! I’ll update the article. Thank you!

@Matt – PIL vs. ImageMagick – no strong personal opinion, but I trust Alec here. I agree that avoiding dependencies is good. RE: SuperImageField — I was hoping someone would have something like this — it would be amazing if you had time to release it in some fashion!

By: Jon Stahl

Jon Stahl — Wed, 03 Mar 2010 17:23:02 +0000

@JohnS — I agree wholeheartedly, and in fact I mentioned it as afterthought: “Somewhat randomly, I also wanted to take note of Kurt Bendl’s useful recipes for limiting the max KB and pixel dimensions of uploaded AT Images and Files. This might be useful and/or worth exposing in a TTW setting.” IOW, Plone already has this capability, it’s just buried very, very deeply.

By: Julian Robbins

Julian Robbins — Wed, 03 Mar 2010 10:12:49 +0000

Great idea, something that I think Plone could have done with a long while back !

My only thought , is that with png's with transparency, you will not want them to be changed to jpeg's necessarily as you'll lose the transparency. It may be worth doing a check in the app, to see if your png or gif files has transparency and make a small flag of this in the results, so that the user doesn't automatically just select 'change to jpg' for each png file.

By: Matt Hamilton

Matt Hamilton — Wed, 03 Mar 2010 09:25:32 +0000

Jon,
A great idea. We have an AT field/widget here at Netsight called SuperImageField that does a number of things that we keep meaning to get around to releasing. This could be a good catalyst for this, and would be good to roll the functionality into the project you describe as I think they would fit nicely. It allows variable image compression, cropping to set sizes, watermarking, etc. Basically an accumulation of a number of features clients have wanted from us over the years. It ain’t pretty, but I’m sure we could sort it out

As for using ImageMagick as opposed to PIL… does it really give better quality? Alec, you are using PIL.Image.ANTIALIAS for resizes right? We already have PIL in Plone, and I’d be a shame to have to imclude yet another dependancy unless really worth it.

-Matt