Thank you very much for your answer. I will describe everything in points to describe the problem as understandable as possible. Forgive my poor english
I sent you a drop box file called “2023-03-28 - Topaz Video AI - Compression Banding” - its a file straight from the camera.
I wanted to use Topaz Video to stabilize files before editing. I turned off all “enhancements” and set the parameters to zero. The source file is 3840x2160. The camera is a Sony a6300/A7III with a maximum bitrate of 100Mbps. After stabilization in Topaz, of course, I get a file with a lower resolution (“auto-crop” function).
I tested this problem on different codecs, different files.
- As an experiment, I ran a file through Topaz with everything turned OFF (even stabilization was turned off - no enhancer, no resolution changes, no framerate, etc).
a) Prores 422 HQ - the problem appeared and the color was changed.
b) MP4 birate 180 (higher than the file straight from the camera) - the problem also appeared, but finally the rendered file bitrate from Topaz Video AI was lower than the file straight from the camera - about 80Mb/s
- The problem is very visible in out-of-focus shots (for example, when I move the camera dolly out of the wall). However, compression also appears on faces, in dark parts of clothes (underarms, for example), in the sky, walls, cars - literally all “smooth surfaces” so to speak - just like overly compressed jpg files. Of course, the problem is less visible on textured items, but still visible when zoomed in. I hope you know what I mean - in the files straight from the camera you can see a slight “noise”. In Video AI files we see smooth, compressed pixels.
It is least noticeable in shots with a lot of detail, where there are no uniform surfaces and no blurred background, etc.
When saving to Prores, we get gigantic file sizes that are difficult to compress. I also tested Prores and files in different formats, but it added a lot of processes to my workflow.
It seems to me that that Topaz sets by itself “the right birate”. Despite the target bitrate (180 Mb/s), the files weigh less than the “negative” straight from the camera.
In other programs, for example in Adobe Media Encoder, we can set the CBR (Constant) bitrate - maybe this solution would help if there was such a function in Topaz Video AI?
Of course, I realize that my cameras are not in the highest league, but you can clearly see the banding and compression in the Topaz Video AI files, which should have a higher bitrate than the files straight from the camera (we should "artificially increase the size of the files to prevent damaging compression).
Maybe “forcing” the program to keep the bitrate constant throughout the file would help? Unfortunately, this also appears in Prores files, despite the fact that they have a gigantic bitrate and weight.
And here’s another example. The left shot is a file straight from the cameras, and the right shot is from Topaz AI.
For the Topaz shot, UHD scaling (after auto-crop stabilization) was enabled.
I brightened this shot so that you can see the difference in the browser.