Repeatedly calling [camera start] and [camera stop] leads to a much greater than linear memory increase over time, and what looks to be a linear increase in CPU usage. By the 5th time you restart the camera, the application becomes almost unusable. This issue is independent of whether you release and reallocate the CvVideoCamera *camera each time you restart it, and also independent of whether you supply a parent view in the initializer. This has been tested in iOS 7 on an iphone 5s with opencv version 2.4.8.
I wanted to post this here before I file a bug report to see if anyone has any ideas about what might be going on.