There is a previous thread with exactly this same issue - unforunately it has been closed.
I have liner notes which appear the correct way up in Windows file explorer, and also when I open them in Photoshop. But in Roon they are rotated 90 degrees. This is how the images originally were before I rotated them with Windows file explorer. It seems that Roon hasn’t picked up the changes (if the changes are indeed saved to the files this way, which you would expect). I tried going to “edit” and then “rescan album”, which ostensibly looks again at the artwork, but it does nothing.
If a Photoshop rotate doesn’t work either, I’m pretty sure it’s a cache issue. You could try delete, recan, check to see if it’s gone, re-add. If that doesn’t work, I think you’ll have to try clearing the image cache. I think you are right that will delete all cached images for that control point, but I don’t remember that being a problem - just marginally slower as you revisit albums. That actually prompts another thought… what do you see if you try a different remote that has not been used to view that image before?
Edit - have you tried renaming the file? I know I had a similar issue with file edits, but it was a while ago. The ‘fix’ was (obviously) the last thing I tried, but I don’t remember which order I tried!
Thanks for the further thoughts. If I use a different remote that has not been used to view that album before, the art appears the right way up!
Regarding the rename, good idea. Renaming the offending file causes it to appear the right way up in Roon - but it appears first in the list of images, not where it should be. Also, when I mess with the images some more (make a new front cover image), then the rotation of the offending file returns to what it was before! If I rename it again…then it stays the wrong way up.
Fun!
I couldn’t find a definitive specification for how Roon orders images (but did find many posts going back five years or more with your contributions!). I gather it looks at file names and tries to do something sensible; this correlates with my past observations. This GitHub link is the closest I found…
Unless you have very many problem images (making it worth the investment in time and headscratching) I think I’d delete all images from the folder, clear the cache, then copy corrected and conventionally named images back in.
This piece of information, however, does make me suspicious that @AndyR’s caching hypothesis is correct. We’ll keep an eye out for your response and are standing by to investigate logs more deeply.