Matching plaster texture

I am trying to match the texture of the interior plaster walls in my house. The underlying material is called button board, I believe. I had to cut out part of the wall to run some wires. I used backer boards and put the piece back in and finished it with tape and joint compound. the fixed area doesn't look that bad, but it is noticeable because I was not able to reproduce the texture using a 1/2 in paint roller. I have attached a picture of the wall texture that I am trying to duplicate. Any suggestions would be greatly appreciated.