May 13, 2008

Newark Picks Shotspotter

[From City picks gunshot detection system - NJ.com]

Newark has chosen Shotspotter for a gunshot detection system over competing systems from Safety Dynamics (SENTRI) and Planning Systems (SECURES).

Gunshot detectors will be mounted on structures over a 7-square-mile area. When triggered, Shotspotter sensors will provide police with the location, number of shooters, and number of shots fired. . . . Shotspotter's Gunshot Location System has also been installed in 27 cities around the country, including Washington, D.C., and East Orange. Newark's neighboring municipality first introduced gunshot detectors made by Planning Systems Inc. in 2005, and deployed a Shotspotter system in 2006, according to Detective Andrew DiElmo of the East Orange Police Department. Both systems are in operation in East Orange.

Gunshot detectors are viewed as a "useful tool" for investigative purposes, and the East Orange police also considers it a crime deterrent, DiElmo said. However, there have been issues about gunshots that go undetected by sensors. "Does it work 100 percent of the time? No," said DiElmo. "We have had incidents where the sensors haven't alerted us."

Posted by rshah at 03:05 PM | Comments (0)

May 08, 2008

Challenge of False Positives

[From The Key Challenge for Video Analytics : IP Video Market Info]

John Honovich points out the importance of false positives. A false positive arises when a smart camera system warns operators of a situation, when the situation is normal. This problem arises when cameras move out of laboratories into real world conditions where weather and external stimuli, such as birds, make video analytics difficult.

Here are some interesting snippets:

Making sure you only trigger when someone is violating is hard because there are so many factors that might set off the analytic besides a valid adversary. To a computer, rain, dust and snow can all generate a similar form to a human being. Quick changes in light or the movement of water (waves) can also generate such forms. A camera that shakes because of the wind or issues with the mounting or installation also can trigger such alerts. The hard part in such analytics is to make sure that these alerts can be eliminated. This is a key metric in testing and differentiating between analytics.

False positives drive up the cost of systems. . . . While it is better operationally to centrally manage alerts, if the system generates dozens or hundreds of false alerts per day, the costs can become prohibitive. Let's say an 'intelligent' camera generates 5 false alerts a day at the cost of $1 per alert (the unit cost to pay a monitor to assess). That's $5 per day, over $1,800 per year and about $10,000 for a projected 5 year lifecycle. If you dozens or hundreds of cameras, this hidden operational cost can be in the millions. And this is not theoretical. This is the feedback you will hear time and again from real world deployments. It's widely accepted that this is improving but it is still the major factor in duing your due diligence in analytics.

Posted by rshah at 01:21 PM | Comments (0)

May 02, 2008

DC Expanding Their Network

[From D.C. Forging Surveillance Network - washingtonpost.com]

The network is expanding by 5000 cameras. It will include 3 to 5 operators watching images in real time. Analytic software is expected to be added by the end of the year. The cameras come from existing networks:

In its start-up phase, the system will include the public schools, the D.C. Housing Authority, the Office of Property Management and the Transportation Department. By year's end, it will expand to homeland security and the departments of Parks and Recreation, Corrections, Health and Fire and Emergency Medical Services. The schools have the largest number of cameras, about 3,600.

Right now DC is still looking for funding and privacy advocates are not happy that the department is rushing ahead without applying prior safeguards. Until now, DC had been the model for the best privacy safeguards. See the article for more or read this nice opinion piece by John Podesta and William Sessions.

Posted by rshah at 03:44 PM | Comments (0)

April 25, 2008

Privacy Protected Surveillance Using Secure Visual Object Coding

[From Intergovworld.com More privacy-boosting technology begets more video surveillance]

Developed by Karl Martin and Kostas Plataniotis, researchers at the faculty of engineering, their secure visual object coding application uses cryptography techniques to encrypt "objects of interest" within video frames -B faces or other features that may be used to identify a person - and store them separately. In order to view the original complete image, a decryption key is needed to restore the object of interest.

The project web site by Karl Martin shows a number of pictures of the process at work. The idea here is to encrypt either faces or complete bodies as a way to protect privacy. For example, surveillance could be monitored in real-time but faces would be obscured. However, this is reversible if a decryption key is used.

The PET application is an add-on designed to work with a front-end video surveillance system that has object detection capabilities. "Facial detection has been around for a long time to varying degrees of performance. Many vendors already offer it in consumer applications like digital cameras so you can focus on faces when taking photos."

They are currently working on implementing their system with the Toronto Transit Commission (TTC).

Posted by rshah at 07:36 PM | Comments (0)