Originally posted by redcurl I would like to know where the origin of the problem lies, I got an interesting link from a dprview member :
Posterization Wow that's an interesting problem!
I'd be curious to see the original file though. It's near impossible to determine what's happening with a JPG alone. Posterization could very well occur at the JPG translation stage, or... there could even be some form or error at the RAW development level. But again... this is all speculation due to the fact that we can't actually see the original file.
The good news is(however) that both most all issues of these types can be rectified.
PS. if you are comfortable with FTP upload, I could setup and account so you can upload the file and hopefully find a solution.