One can ask Koha to allow for multiple cover images, but this can look very messy, and for a lot of our older books (pre-2000?) there are no covers. It would be great if Koha could 1. Only display one cover, but from multiple, possible sources. 2. Look on the internet for other possible images. 3. Cover images to be a a reportable feature. I.e. you run a report and get a list of books without covers. 4. For an option to fix lack of covers by batch jobs. I know the above are big asks, but think about how much better Koha OPACs and our collections would look like? The end user might think that Koha isn't "good enough". Maybe the solution is that all cover images need to be stored locally, and then Koha uses the local database of images? The above comes from a librarian who has nearly no knowledge of coding, but 20+ years of experience with library users. As things stand at the moment, it might look neater for us to turn _all_ cover images off. I appreciate that if you only ever buy books from Amazon, and only have popular books (or fiction) this is not a problem, but for a specialist, academic collection like ours this problem will only get worse the more books we are adding. Currently 100k of 250k of volumes are catalogued! Help!
Koha gets its cover images the way it does largely because the license for services like Amazon and Google cover images requires (last we checked?) that the images not be copied and stored off of those sites. So Amazon will let you use their cover image but only if you're loading it from their server: "You will not store or cache Product Advertising Content consisting of an image, but you may store a link to Product Advertising Content consisting of an image for up to 24 hours" https://affiliate-program.amazon.com/help/operating/policies?pf_rd_p=533f99bc-124a-40f3-90a1-485af6c938a7 I see that Aspen Discovery appears to store the source of a "successful" cover (e.g. coce_google_books) so that the system doesn't need to look on the fly for a working cover source like Koha does. But I don't know how Aspen "decides" which source is the best option in the case where there are multiple. The CustomCoverImages and LocalCoverImages preferences move the copyright compliance responsibility, theoretically, to the person running the Koha installation (rather than the Koha project) and those would be the features you'd want to use if you wanted to make sure your covers appeared. I find it difficult to imagine any way for Koha to search the internet as a whole for available covers. None of this is to say that I disagree with your frustration about the issue. I 100% agree that it's very messy.
Thank you, Owen. It's always good to know why something has been implemented in a certain way. Promoting books which are purchasable by Amazon should be in their interest, of course, but I can think of legal hawks who would have a field day pulling this apart. If for Aspen local images are stored, maybe there can be a rethink for Koha? With regard to how Koha might be able to search the internet for covers. It might need to be semi-manual/semi-automatic process, and one could use "crowdsourcing" to achieve this: 1. A process in Koha checks for cover image. 2. If no cover image, to search the web by ISBN for an image. [this won't work for many pre-1970s books, as without ISBNs, but it would tackle 50+ years of books/book covers!] 3. If image found, show on OPAC as "unapproved". 4. Two humans needing to confirm that the cover is appropriate/correct. 5. Some of these humans could be end-users of Koha; they would need to be logged into their local system to approve a cover. Complicated maybe, but maybe not impossible to code?