Mike, I used the one called DeJpeg. It pushed the reduce artifacts slider up and it worked pretty well.Sorry for lack of info...
In my original, the overall yellow cast is easy to balance. What my issue is are the bands top to bottom on the left edge. I did have to downsize this to upload, and the forum software might not allow this to stand out. I am working on the background as I am able to make the people almost perfect .......given what I have to work with.
Larry when you say Topaz jpg... is that DENOISE ? or JPG ?