Drop first 20 frames before mse compare.

[dksslq]

Avoid calculate mse of camera initialization and adaptation phase

[davidplowman]

Hi, thanks for this PR. I agree that this is probably a sensible change to make so am happy to merge it. Could you just check that you've followed the contribution guidelines - I think the only changes to make would be to sign off your commit, and to target the PR at the next branch. Thanks again!