Changes the working resolution of the camera.
This will automatically add a two second delay to allow the camera to adjust to the new resolution.
Where Blackfin is the name you have given to the device in Project Designer.
Since it takes a number of seconds for the camera to settle down after a resolution change then it is not something that you should be doing on a frequent basis.
Project Designer allows you to set the default resolution - so there should be little reason to change it within your own code.