I work mainly in film restoration and was running some tests over early Winx episodes for upscaling techniques. I have the native file (720x576p) of S01E01 and used a restoration workflow in conjunction with Topaz and/or other softwares (576 restored, 576 to 1080, 1080 restored, 1080-UHD) and the results don’t get to the level of a video I found on YT (with YT compression!) especially with fine details (eyes, face traits…). This was uploaded by MagixJourney and the title is “SEASON 1 - 4K REMASTERED | WINX CLUB - FULL SEASON IN ENGLISH” (can’t attach the link on this forum).
I dug back and read some techniques used a few years ago like R-ESRGAN with Vapoursynth, but even when trying those the results don’t get close.
Any idea how this could have been achieved?