Saturday, September 6, 2008

Intelligent video analysis at the edge

In Sam Pfeifle's recent Security Systems News article ( "Milestone aggregates analytics" he quotes Milestone Systems' Chief Marketing and Sales Officer, Eric Fullerton:

"It's a myth," he [Eric] said, referring to the trend toward putting analytics on the edge, on cameras or encoders, "to think that you're going to reduce what you send back over the Ethernet. You're going to need to have the full recording." But, he said, those analytics are great for creating metadata and tagging video as it's streamed back.

Eric is spot on. People are going to stream video to a centralized recording system, regardless of whether it is an NVR or Direct-to-iSCSI, in which case there is no way you are going to send alarm video only. The only exception to this is if you're Recording at the Edge, as in the case of Bosch's encoders with embedded storage. In this scenario video is never transmitted across the network to be recorded, so analytics at the edge does not affect this either way. If you consider a telecoms operator with 5,000 cell towers, with the need for analytics and recording at each location, then analytics at the edge becomes very attractive, with the benefit of the edge sending the actual alarm to some centralized point for processing.

Eric is also completely right about the critical value of metadata, which is information that adds value to the video. And edge devices have the responsibility of creating and sending this metadata, which is precisely what the Bosch encoders and IP cameras do. Data like 'A red object stayed in this area of the image for 3s, then moved to this other area for 30s'. The secret behind unlocking the power of this metadata is not only in aggregating them to provide better false alarms, but also in being able to do forensic searches. Such searches are always done on recorded video, and by definition are done after the fact. They allow you to mine months of video searching for whatever you want, even if you never thought of setting up the rule months ago. For example, 'tell me everytime someone parked in front of the main gate in the last 4 weeks'. Bosch has developed such a tool, called Forensic Search which is a licensable part of Archive Player. I personally find this feature to be invaluable because it allows me to record a day of video from a real camera with real and typical events I want to detect, and then to test whether my rules work. I get instant results because I don't have to wait for the events to happen in real time.

I agree that metadata is critical, which is why all Bosch devices stream copious amounts of it, because, more often than not, you don't know what you're looking for until it's happened and then you're busy looking for a needle in a haystack because your rules weren't set up before.

Finally a comment on pricing, or as Milestone's Channel Marketing Manager Mark Wilson alludes to, value. Yes, prices will continue to drop while accuracy increases. For unit costs to drop sustainably I suspect the number of deployments will either have to rise or the cost of sale will have to drop. It's these reality dynamics that have brought Bosch to the point of delivering embedded intelligent video analysis in all our encoders and IP cameras, with a functionality set and price point that is targeted at the mass market - the everyday applications like watching for people loitering, smoking on fire exits, leaving shopping carts or boxes by doors, people but not small animals crossing a 5 mile perimeter fence line or cars parking next to it.

Although I agree analytics could live anywhere, there is a strong argument for keeping 'everyday analytics' at the edge, including metadata generation, bandwidth minimization via recording at the edge and the sheer economies of scale of dividing the workload among many tiny edge devices, not to mention the elimination of the single central point of failure.

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