Ticket #5238 (closed Bug: wontfix)

Opened 10 years ago

Last modified 7 years ago

Image type does not support interlaced png

Reported by: justizin Owned by:
Priority: major Milestone: 3.0b2
Component: General Version:
Keywords: Cc: grahamperrin


ATImage reports that it doesn't support interlaced png, a perfectly good graphics format. we should do our best to fix this. Perhaps it's worth considering supporting PyImageMagick library either parallel to or instead of PIL, if it is available.


There is a bit of banter on this topic, and it sounds as if ImageMagick is as good or better than PIL in all cases, including support of interlaced images, generates less aliased thumbnails, etc..

Change History

comment:1 Changed 10 years ago by hannosch

  • Milestone changed from 2.5 to 3.0

comment:2 Changed 9 years ago by justizin

  • Component changed from Content Types to Infrastructure

I heard some rumblings that both ImageMagick and PIL were originally supported, but ImageMagick was dropped. I think at the very least that there should be framework in place for dropping in replacements for things like this. Aside from ImageMagick, options for image manipulation in F/OSS include:


 http://www.gegl.org/ (from GIMP)

I believe Chimera supports the concept of filters, which I know are in both PIL and ImageMagick, am pretty sure are in GEGL, and would bet are supported in GIL as well.

Also, I'm curious if this is really 3.0-bound. I don't propose to remove support for PIL by any stretch, but only to modularize its' use such that it should be trivial to drop in a replacement, and this seems like developer-focused, 2.5-land or 3.5-land. It doesn't seem like a big enough deal to wait for 3.5, and truthfully, it is a bug which affects the adoption of Plone for us now - some perfectly valid image formats are simply not supported, or not supported correctly.

In short: my graphics geeks are getting very touchy about their TIFF and TARGA files not being supported. I've gone to the extent of personally reviving the PyImageMagick project from the archives of UW or somesuch, and may even seek a project grant with ACM SIGGRAPH to complete this.

This is one reason, btw, that I am in favor of having post-.5 releases with additional developer features, they don't call it the tens place for nothin'! ;)

comment:3 Changed 9 years ago by wichert

  • Status changed from new to closed
  • Resolution set to wontfix

I suggest putting your efforts into getting support for interlaces gigs in PIL. Plone uses that library and should not implement this itself.

comment:4 Changed 7 years ago by grahamperrin

  • Cc grahamperrin added


Recreate image scales - fails. Highlights from  http://pastebin.com/f7d6419ed :

  • IOError: cannot read interlaced PNG files
  • - __traceback_info__: (<Field image(image:rw)>, <ATImage at /centrim/media/2004-05-11-saitek/P1020026.png>, 'image_mini', 200, 200)

Curious. The point at which it fails P1020026.png is not a recent addition to our site, it's been there since 2007, and I have recreated image scales — without difficulty — a few times since then.

comment:5 Changed 3 years ago by davisagli

  • Component changed from Infrastructure to General
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