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Horrible posterization and colour banding.
Hi,
Please can anyone help?
I just finished editing my movie, “Commuting” on Final Cut Pro 7. The footage was shot on a Canon 5Dmk11 and the screen grab attached is from an outputted Quicktime
(H264 1920×1080):
As you can see, there is some horrible banding and pixellation in the image which is not nearly as evident in the raw file. Is there anyway of treating this?
Many thanks
Jim Canty
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3 Replies
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Pixellation is most likely a product of the data rate. Banding is an 8 bit versus 10 bit issue often.
Did you create the H264 in Compressor or via quicktime conversion? What are you sequence, edit codec and export settings? To many variables and not enough info to make any better guesses.
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Thanks Michael,
Actually the movie was cut on Avid – outputted as a1920x1080 H264. I then imported into FCP 7 in order to do some colour correcting. Looking at the outputted file from Avid, though, it appears that the pixellation/banding is already evident.
Avid issue?
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The issue has more to do with your acquisition. The 5D shoots to h.264 which is inherently 8-bit and heavily compressed. That said, when you exported from the AVID to h.264, you introduced another level of compression which will make it worse. The best course of action would be to export it from Avid as a DNxHD file (or same as source). You can then convert that DNxHD Quicktime to Pro Res if you need to further work on it in FCP. It’s a lot of steps in conversion, but you’re keeping the bit rates high which will reduce the amount of digital artifacting.
The fact is, the banding probably was present in the original but just much less noticeable because of the exposure, and also it’s less noticeable on the camera’s viewfinder than it is on a larger monitor. As you color correct the footage, it will become significantly more noticeable. A few tricks to deal with that would be to dither the footage. Add a layer of noise, and bring it’s opacity level way down. If you have after effects, you could also try making a mask shape with noise and tracking the areas of significant banding. It would take time and work, but would keep you from having to drop noise over your whole image.
Richard Sanchez
North Hollywood, CA“We are the facilitators of our own creative evolution.” – Bill Hicks
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