I understand Rhea is designed for 4k upscaling, but I have used it for upscaling 480P to 2X resolution and so far its has produced the best results I have seen for upscaling DVD.
I don’t understand why this thread has no comments. My experience in comparing the 7 different primary models on a large (20+) assortment of 240p to 480p and even 690p DVD scenes was unanimous upon review, that Rhea1 was vastly superior. Furthermore the history of the Rhea model being a combination of Proteus and Iris (albeit taking longer to process) cements its legitimacy as king of quality.
On the other hand we have users who prefer quantity over quality. I’m going to label these the “Golden Corral” users; who could probably get their needs met in a GitHub forum (or a buffet line).
The topic of ideal set-ups to speed Rhea1 or Rhea2 up sound like great threads (both PC and Mac FYI). But the topic of “good enough upscaling” versus “the very best upscaling” should be split into two threads, as they are akin to consuming calories via fast food means versus fine dining. i.e. categories that never meet.
Thanks for listening,
Michael
Rhea is great and has the the potential to be the only one amazing recovery Upscaler that can replace Proteus + Iris…sometimes, actualy it can’t replace, Rhea has great strenghts but also “bugs” and needs more training.
Rhea XL is only usable with V5.4 and V5.5, but this versions are bugy, so I switched to 5.3.6 and can’t use Rhea XL.
Both Rhea models have the disadvantage that they produce slightly too thick “edges”, It seems like NYX ist part of Rhea.
Rhea is optimized for 4x, but many wants 4k from 1080p source and not 8k, so 8k gets scaled down to 4k when you set 4k in Rhea and this leads to the well-known “plastic look” What it needs is a additional trained model for 1080 → 4k, and 480p to 1080p or 480p to 1440 (WQHD)
Rhea XL keeps more details than Rhea V1
Rhea “integrates” noise into it, which is a good approach keeping max details, but it’s to strong, before Rhea scales up a better base denoising would have to be done, otherwise when source is noisy it often leads to a “dirty look”.
Rhea has no face recovery like Iris. However, face enhancement is not always positive and can lead to degraded faces, usually when there are too few pixels for face rendering. Rhea should get a face recovery, where user can adjust sensitivity + strength and a switch to turn it off. Without face recovery, Rhea can never replace Iris.
Rhea XL sometimes has problems distinguishing background from foreground, which leads to partial artifacts. Strange, Rhea V1 does not have this problem.
If you have lettering in images, Rhea XL can do bad things with it, it distorts it to illegibility, Rhea V1 is here better.
False. Rhea does do special face enhancement. Proteus does not.
In my testing of Rhea on DVDs, I could only get it to make monster faces (On background subjects), or focused faces where they were supposed to be blurry from being background subjects. I quickly moved on since it was clear Rhea would be useless to me. When Rhea XL came out, I tested it and got similar results. But of course, understanding that Rhea XL is meant for bigger sources than DVDs.
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I wrote earlier it does face rec. then others correct me no it does not and better faces just comes from normal improvement the model does. So I don’t know now whats the case now, when ist does, then not good.
I use all three models and pending on source Rhea can give the best result, sometimes not and I get monster faces as you described, but you can also get disorted face using Iris.
yes can do Iris too, that’s a problem, but I also got awesome results where no Proteus or other model can do it, and that is certainly what mehranariani is talking about.
Until they make the UI able to set different models for different sections of the movie, Rhea will mostly just be a happy idea. What I hope to convey is that I can get better-than-source results on entire movies and shows with Proteus, but I cannot with Rhea and Iris. I can get specific scenes to look better with those two, but until we are given the tools to more easily define where those models will be used, it’s simply too much effort to make them useful.
Of course defining what models should be used on what sections of a source movie, would also take a lot of effort. It would be considerably less than what we have to do right now to get mixed model results though.
A bit late to the party but due to time constraints (work) I didn’t have much opportunities to test the newer TVAI builds.
At first glance Rhea did look extremely great. Giving it more different material there still are quite some severe flaws, occasional “monster faces” on low res sources being one on them (obviously taken over from Iris MQ), but also the repetitive low res pattern issue that we know from Iris MQ.
And Rhea does a bit of over sharpening here and there (which can be diminished by setting parameters individually). Rhea look a bit like a crossover of Iris MQ and Proteus with a bit of NYX added.
Overall I do like the model and think it has quite some potential - unfortunately as we all know there’s most often few to none improvements in the last two years to existing models after they have been released.
Examples:
-
The good:
-just WOW
-really good work at denoising and general cleaning up this extremely difficult source and still gaining details without changing the original
-a scene where faces did work well -
The bad:
-ugly repetitive patterns of low quality textures in the grass
-the same in the snow - looks a bit like a moon surface…
and zoomed in:
-
And the ugly:
-monster face / creepy eye
-look at Dave’s left pupil - also the glasses on Fletch look like “stamped in”
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One last thing (No, I’m not Steve Jobs 
):
I found that using Rhea at 1x size without upscaling does still deliver a very good cleanup of the source with gaining some details but mostly leaving faces alone, so nearly no monster faces with that:
-not bad for the video being still at original SD size…
Even for that small low res face the original character is fully maintained at 1x resolution with Rhea (so here it’s behaving more like an Iris LQ / Proteus /Nyx crossover). But it does introduce jagged edges on sharp lines like the glasses - albeit only visible in such extreme zoom.
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