• PSD is a proprietary format. Wouldn't this need WMF-Legal review?
• Can PSD files contain anything which automatically loads external files? Security review.
• Would we be able to provide a way to preview the contents of a PSD or generate thumbnails of them? Or are these just going to be downloadable files?

In T91914#1098693, @Krenair wrote:

• Would we be able to provide a way to preview the contents of a PSD or generate thumbnails of them? Or are these just going to be downloadable files?

I think the best way to go about this would be to automatically export an (probably .jpg) image out of the .psd file. It shouldn't be just a downloadable file but a Wikimedia image like the rest - it might also be used in articles.

I think your first two points are correct.

My knowledge regarding this might be a little bit stale (2 years old), but last time I wrote support for PSD uploading/thumbnailing using open-source software on another website, this was the status quo:

• If the PSD file is saved with the "maximized compatibility" option selected (in Photoshop or equivalent), all is well for thumbnailing. Basically "maximized compatibility" means that the authoring software will include a flattened JPG version of the content inside the PSD. Very easy for imagemagick or similar to extract the thumbnail.

• If, however, the PSD file is saved without the "maximized compatibility" option selected... This is quite common because not only people creating the content often wonder what this cryptic option means, it always makes the files larger. In that case the PSD, with its layers and effects has to be interpreted in order to generate a thumbnail. Unfortunately no open-source software does this well yet. Some effects will be missing, and more importantly, fonts will be all over the place because those are dynamically referred to.

• I'm not a license expert, but something to keep in mind is that PSDs can include references to proprietary fonts (the vast majority, really). It will always fall back to what's available on the viewer's computer, but it's definitely a question to explore (is it truly free content if it contains references to commercial fonts?). Maybe I worry too much, but I'd certainly like to hear expert opinion on the matter.

Now, what you can always do for the thumbnails is ask the uploader to provide one if the PSD isn't saved with "maximized compatibility". That's what we did at the last place I implemented this. Combined with a nice explanation about the option in their authoring software, people can easily adapt their workflow to make uploading PSDs faster. Alternatively, you make the thumbnail optional. Either it's there thanks to "maximized compatibility", or the uploader provided one manually, or it's just missing and a generic placeholder will be there.

As for security, I've never heard of PSD security vectors or the ability for it to fetch external content, but a security review will be required regardless. The spec for the format looks surprisingly digestible: http://www.adobe.com/devnet-apps/photoshop/fileformatashtml/

In T91914#1099629, @Gilles wrote:

I'm not a license expert, but something to keep in mind is that PSDs can include references to proprietary fonts (the vast majority, really).

IANAL but pretty sure references to nonfree resources are fine. Any SVG file can do that; even wikipedia.org's CSS files do that. Embedded fonts are more problematic (although in the US, fonts are not necessarily copyrightable), but either way this is a content issue, not a format issue: you can put proprietary elements into any image. That needs to be dealt with as part of curating the uploads.

Now, what you can always do for the thumbnails is ask the uploader to provide one if the PSD isn't saved with "maximized compatibility".

Or just disallow such uploads.

You can upload the file here
https://commonsarchive.wmflabs.org

And add the template:
{{Commons Archive|My_raw_file.dng}}

in your image in commons, look this example:
https://commons.wikimedia.org/w/index.php?title=File:Agraulis_vanillae_at_Isla_Margarita.jpg&action=edit

Also, you can upload any file type like NEF, PSD, FLA.

In T91914#1098693, @Krenair wrote:

• PSD is a proprietary format. Wouldn't this need WMF-Legal review?

Its also quite possible the commons community will be opposed to this imo. Or at least parts of it might be.

As an aside, image magick does claim (at least token) support for psd files.

We do allow xcf format for this purpose (For those people who use the GIMP).

Marked as blocked on development, as we don't have a PSD handler.

In T91914#2424768, @Bawolff wrote:

In T91914#1098693, @Krenair wrote:

• PSD is a proprietary format. Wouldn't this need WMF-Legal review?

Its also quite possible the commons community will be opposed to this imo. Or at least parts of it might be.

Let's ask the community.

https://commons.wikimedia.org/wiki/Commons:Village_pump#Fall_2016_interest_poll_for_PSD_support_in_MediaWiki

Cleaning this a little bit to focus on technical aspects, as it's doesn't seem there is currently no willingness from Wikimedia projects to endorse such proposal.

Yet, the idea to develop an multimedia handler extension to support PSD files is a valid feature request for MediaWiki installations outside Wikimedia.

Scope part 1: Files (Scope of Wikimedia Commons)

"Uploaded files are within scope only if they comply with all of the following conditions. Every file:
Must be a media file.
Must be of an allowable free file format.
Must be freely licensed or public domain.
Must be realistically useful for an educational purpose.
Must not contain only excluded educational content."

Nothing more to add,

PS: Yes, outside Wikimedia Movement could be... however TIFF files is a good substitute for most of PSD functionalities, and you could create a orientation to that. (even Photoshop Lightroom creates TIFF files to their users edit it at normal Photoshop)

Okay, my task repurposing idea wasn't optimal, as we'd lost a lot of interesting context about the Commons community expectations.

Let do this the other way around and keep this task for PSD on Wikimedia.