Remove Banding in sky at DVinfo.net

Mike Harrington · March 18th, 2011, 11:01 PM

i need a bit of help removing some banding in a bright blue sky

I shot some fighter jets on RED, and converted to Cineform and my final output is PhotoJpeg Quicktime (not my choice)

I am thinking the 12 bit to 8 bit drop is leading to the banding...
any clues as to get rid of this crap
I know one way is to implement some type of dithering(not sure how)
Ideally there would be a better way to compress the data to 8 bit....perhaps

thanks

David Newman · March 18th, 2011, 11:24 PM

Yes, PhotoJPEG not the best choice, but it will do if you let the bit-rate climb. Place the CineForm master into an AE composite, set the comp to 16-bit mode. Add a 16-bit noise filter with 0.4% noise (1-LSB of 8-bit worth of noise) then encode to PhotoJPEG at a high quality setting. If you still see banding, bump the noise. This is the dithering you need.

Mike Harrington · March 19th, 2011, 02:22 PM

thank you David....
can you explain the logic behind the .4%
specifically decoding what you mean by 1-LSB

Thanks again

David Newman · March 19th, 2011, 04:28 PM

8-bit is 256 levels. 1-bit or the LSB (Less Significant Bit) 1/256th of the full range. 1/256 = 0.0039 or approximately 0.4% of full range.

Mike Harrington · March 19th, 2011, 05:31 PM

thanks...appreciated as always..
might delve more into this using google later..

March 18th, 2011, 11:01 PM	#1
Mike Harrington Regular Crew Join Date: Jan 2009 Location: Edmonton, Canada Posts: 91	Remove Banding in sky i need a bit of help removing some banding in a bright blue sky I shot some fighter jets on RED, and converted to Cineform and my final output is PhotoJpeg Quicktime (not my choice) I am thinking the 12 bit to 8 bit drop is leading to the banding... any clues as to get rid of this crap I know one way is to implement some type of dithering(not sure how) Ideally there would be a better way to compress the data to 8 bit....perhaps thanks

March 18th, 2011, 11:24 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Re: Remove Banding in sky Yes, PhotoJPEG not the best choice, but it will do if you let the bit-rate climb. Place the CineForm master into an AE composite, set the comp to 16-bit mode. Add a 16-bit noise filter with 0.4% noise (1-LSB of 8-bit worth of noise) then encode to PhotoJPEG at a high quality setting. If you still see banding, bump the noise. This is the dithering you need. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

March 19th, 2011, 02:22 PM	#3
Mike Harrington Regular Crew Join Date: Jan 2009 Location: Edmonton, Canada Posts: 91	Re: Remove Banding in sky thank you David.... can you explain the logic behind the .4% specifically decoding what you mean by 1-LSB Thanks again

March 19th, 2011, 04:28 PM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Re: Remove Banding in sky 8-bit is 256 levels. 1-bit or the LSB (Less Significant Bit) 1/256th of the full range. 1/256 = 0.0039 or approximately 0.4% of full range. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

March 19th, 2011, 05:31 PM	#5
Mike Harrington Regular Crew Join Date: Jan 2009 Location: Edmonton, Canada Posts: 91	Re: Remove Banding in sky thanks...appreciated as always.. might delve more into this using google later..