Two possible suggestions: - Sound processing (i.e. more than just images) - Commercials tend to repeat, so you could you this to get another metric for a match. Of course, it wll need a fairly well maintained database...
I am intersted in signal/image processing, so it'd be nice to have a bit of a page spring out from this about the current technical means/ideas for implementing commercial detection.
Do commercials have Teletext/Subtitles? If so could there be a database of Ad scripts?
Commercial Flagging Performance
I think it would be great to add in a section on the various performance penalties that the various commercial flagging options add. Obviously blank-frame seems to be the easiest, and scene change probably isn't too hard, but the logo detection probably yields some processor hit.
Another topic that I often don't seen mentioned is the accuracy of the commercial skip function given various recording qualities. I tend to record a plethora of kids shows in low quality and have noticed that the commercial breaks are missed more frequently on lower quality recordings.
I've seen several networks (increasing in numbers) that have started adding or removing commercial skip identifiers around their show advertisements. Often the commercial skip detection leaves the advertisements for other ABC shows just prior to the real show returning from commercial.