That appears to be a Confederate colonel probably in some part of the CSA where they had difficulty obtaining regulation insignia, such as the Trans Mississippi West. He could also be a militia colonel. Three stars on each side of the collar to me means a colonel, whereas a general had three stars in the wreath.

Perhaps this officer employed larger stars than normal because he wanted to be sure his men recognized his rank. Another possibility is this is what his dear wife came up with and he felt obligated to wear them.

Bruce Nichols