Ben_B
Veteran
Hi, thought I'd start this thread to see what people are doing either on set or in post to avoid blockiness and 8-bit banding in the sky and other places. It's present in lots of footage and can be highly exacerbated by color correction.
Here is a screen grab that shows the problem pretty heavily post color correction. You can see blockiness between the building and the flag, as well as lots of blockiness on the edges of the bands in the sky.
Yikes!
My primary method for removing this issue in post is what I call the "two layer" method. You attempt to isolate the problem areas to be edited separately, whether by keying, rotoscoping, or by using a brush tool of some kind. Then you apply your color correction (and problematic filters like post-vignetting, seen here) to the problem area separately . Then you apply a compound blur or some other non-distorting blur (that blurs while keeping everything in its place, gaussian probably won't work too well) to the layer that you've isolated the sky or other problem area on.
Here are the results of this process, using color keying. You can still see banding in the sky, but all of the blockiness of it is gone, and it's much cleaner. The blocky artifacts between the building and the flag are also gone (and keep in mind that they MOVE on the original footage, the remaining artifacting does not.) I could probably go in there with a brush and clean this up more, but I feel like it's satisfactory, especially compared to the original. I assume you must do this with 10-bit (after transcoding) footage in a 10-bit (or greater) environment or otherwise there is no point...you'll get the problem no matter what.
Oh random note, this is a 720p clip that is being uprezed in a 1080p timeline so that's why there is some artifacting on the flag and the resolution of the building really probably isn't what it should be. My final output for this project is the web so I am not too concerned...played in a window it looks great, and full screen after compression will probably be about the same as the other clips.
Here is a screen grab that shows the problem pretty heavily post color correction. You can see blockiness between the building and the flag, as well as lots of blockiness on the edges of the bands in the sky.
Yikes!
My primary method for removing this issue in post is what I call the "two layer" method. You attempt to isolate the problem areas to be edited separately, whether by keying, rotoscoping, or by using a brush tool of some kind. Then you apply your color correction (and problematic filters like post-vignetting, seen here) to the problem area separately . Then you apply a compound blur or some other non-distorting blur (that blurs while keeping everything in its place, gaussian probably won't work too well) to the layer that you've isolated the sky or other problem area on.
Here are the results of this process, using color keying. You can still see banding in the sky, but all of the blockiness of it is gone, and it's much cleaner. The blocky artifacts between the building and the flag are also gone (and keep in mind that they MOVE on the original footage, the remaining artifacting does not.) I could probably go in there with a brush and clean this up more, but I feel like it's satisfactory, especially compared to the original. I assume you must do this with 10-bit (after transcoding) footage in a 10-bit (or greater) environment or otherwise there is no point...you'll get the problem no matter what.
Oh random note, this is a 720p clip that is being uprezed in a 1080p timeline so that's why there is some artifacting on the flag and the resolution of the building really probably isn't what it should be. My final output for this project is the web so I am not too concerned...played in a window it looks great, and full screen after compression will probably be about the same as the other clips.
