Methods for determining a difference between a reference scene and a test scene are provided. An automated process calculates a power of the reference scene and a power of the test scene. The difference between the power of the reference scene and the test scene determines whether there is a variance between the reference scene and the test scene. Variance can be reported to allow further evaluation of the test scene. For example, if the difference exceeds a threshold, the automated process may provide the test scene to a human inspector for further evaluation. Alternatively, the test scene may be provided to a computer for further evaluation.
Methods for detecting and tagging scene changes