I’ve searched the forum and found a few threads discussing artwork resolution, and whether it can be improved. I’m interested to know if there is an all-in-one guide on what settings to use to improve artwork for new content, but also to upgrade the artwork for the whole of the current library without screwing anything up.
This has been prompted by me noticing that vast difference in artwork quality in my Infuse/ATV library, at both ends of the TV resolution spectrum (I have an old 720 plasma as well as 4K OLED). Of course on the 4K TV the ATV is silky smooth at a 4K GUI, and the posters have gorgeous detail. But even on the old plasma, it’s obvious that the film posters, scraped from the same source, are much better in Infuse even on a 720 display (I use the Estuary skin).
I gather that quality issues in Kodi might be fixable to some extent by adding a few lines to advancedsettings.xml, but I welcome advice on how best to approach this, and if there is potential with the improved performance of the V that I could take advantage of? Thanks.
To test I would suggest to duplicate an existing file in your library just changing the name or location. You don’t actually have to copy the file but rather just name a text file as if it was a video if that is prefered. This should give you an opportunity to see what the current cache size settings look like next to updated ones. Do note that Kodi will only re-cache any given file name once every 24hrs so if you want to try several options you should use different file names or paths when you change something. If you find settings you like better than stock you can just delete the Thumbnails folder and restart Kodi to force an update for all items.
thanks, I am making some progress, but it looks to me like the downscaling is really poor. I scanned in a few non-library 4K titles that have HD versions in the library to do a side-by-side comparison, and changing the imageres settings has a distinct improvement for the large-format poster view (not as good as Infuse, but much better than default). However, if I switch to a poster wall view where the artwork is downscaled, I can see that the quality has fallen off a cliff, the pixellation is terrible even with the higher-res starting point. Is that something that can be improved?
The controls the end user has access to (ie advancedsettings.xml changes) affect only the generation of the cached files themselves. If you check the files sitting in the Thumbnails folder on a PC you will see that the quality of those should be okay. The issue is the software that pulls the cached images and does the final resizing for the live view is not great. From what I remember from testing it last it was an issue where the more it had to downsize the worse the output looked. This of course leads to a bit of a catch-22 as you can only really optimize your cache image dimensions for views that have images in one particular size. Default views in the OSMC skin usually have slightly smaller artwork sizes than Estuary hence why I made the skin distinction.
What is really needed is a better scaling solution for that final screen render but if recall correctly I had been told in the past that there wasn’t a viable solution for an update to this. Perhaps @sam_nazarko is aware if this situation has changed.
thanks for the explanation. I’ve not noticed it before, but I’ve now realised how much better the poster wall is in Estuary for my 1080 kitchen TV that is served by a Shield. The default-setting artwork via the Shield is far superior to the Vero in the poster wall view. I tried to capture this via a screenshot, but when I take a screenshot from the Vero, the result is perfectly fine. But what I’m seeing on screen is far inferior, e.g. the figures of Batman are a pixelated mess on screen, but are rendered cleanly in the screen shot.
[EDIT: via my 4K TV, in the TV’s pure 1080 mode the images are badly pixelated for the Vero in a 1080 GUI, if I enable the TV’s upscaling the images are much better. On my 720 TV, the artwork is very blocky]
I’m not sure how much OSMC can improve this on their end.
When I looked into this awhile back it seems like it’s more of a Kodi thing than an OSMC, but I’m not a dev so who knows?
I do all my posters and fanart myself and store them locally (-poster.jpg, -fanart.jpg, etc.) and I would size my fan art to 1920x1080, have the skin set to 1080p, and make sure cache size in XML was set to 1080 and it still compresses the images!
So when you save an image as a .jpg most software will use a default setting at 90%, which looks just fine, but what concerns me is that I think Kodi uses some really aggressive compression to save the images to the cache, so even if it doesn’t resize them (which is an issue too) it still makes them look like garbage.
If you want a good test, try using the OSMC wallpaper as a fanart for a movie.
It has a lot of angles and will look great being pulled into the skin as is, but once it gets cached the angled edges look horrible.
thanks, so in summary it seems I can improve artwork quality in those views where there is not a lot of re-scaling by modifying my advancedsettings.xml file, but in any view where there is a lot of re-scaling I’m going to be stuck with low quality, and the high quality I see with Infuse/ATV is not currently achievable with Kodi?
This has been discussed internally by us a while back and yes, it seems fanart/image scaling in Kodi is not optimal on non-OpenGL or Direct3D platforms: GUI: improved image scaling algorithm
To my knowledge, nothing has changed about this from the Kodi side of things.
Thanks to the suggestions posted earlier I’ve been able to make some improvement to my Estuary-skin artwork, though it seems that default OSMC settings do not provide the best that can be achieved with Estuary, even if that best is not that great for re-scaled artwork.
Given the prevalence of 4K displays, it would seem that there is substantial scope for improvement in this area, but now that I’ve discovered that re-scaling the 1080 GUI via my Panny OLED gets rid of the bad pixelation in the wall-view posters, I have a workaround at least on that display.
