How does Bloom store image license metadata?

I’m checking a long set of books to make sure that the image licensing information is consistent. I’d rather not inspect them one by one, so I thought I would write a script to extract the relevant bits of metadata from each PNG file.

I can find creator and copyright holder information in the PNG metadata, using the Imagemagick “identify -verbose” command. I can’t find any indication of the license, however. Can you help me see what I’m missing?

Try exiftool. You can see how we use it in the script that builds the Art of Reading collection.

For the Bloom code that reads licenses, see https://github.com/sillsdev/libpalaso/blob/master/SIL.Windows.Forms/ClearShare/MetaData.cs

In case you missed it, Bloom has a command to apply the same license info to all pictures in a book. That might be useful if you need to fix some up. There’s also a command to update the license information on the credits page to match all the images in the book…you could use that to check them all quickly.
Still book by book, but at least not image by image.

Thanks, John and John! exiftool looks great, and those are useful commands to have available.