Time-saving preview of surveillance videos

City View

Article from Issue 195/2017

Rather than stare at boring surveillance videos, in which nothing happens 90 percent of the time, Mike Schilli tries the OpenCV image recognition software, which automatically extracts the most exciting action sequences.

In my home city of San Francisco, hardly a day goes by without hundreds of cars, garages, and homes being broken into. Instead of getting upset about this, I tend not to keep anything of value in easily accessible places, and I have also installed security cameras so that I can peruse the video footage of thieves at work for my personal amusement.

Wireless, Even

Of course, installing a security camera is no easy task, because you need to install a cable and route it to the monitor. Although the camera itself often communicates wirelessly with the control panel, it still needs a power supply, and a power supply is not easy to come by in hotspots such as the underground parking lot or the stairwell.

Recently, a company called Arlo started to sell child-fist-sized, battery-powered cameras [1], which amateur detectives can simply hang up using a magnet (Figure 1). These pocket wonders wirelessly send recorded videos to a hub at a distance of up to about 100 feet, which in turn sends the data via the Internet to a server, from which a variety of smartphone apps or a website transfers the data to the user's screen on request.

Figure 1: The pocket-sized Arlo camera fits into the smallest cubbyhole and needs no power supply.

Conservative Operation

To reduce the load on the four lithium batteries powering the camera so they can last for about one month, the camera is allowed to wake up about a half a dozen times a day if it detects motion in its vicinity and then transfer a one-minute video. You then download the movie from Arlo's website (Figure 2) to see thieves, say, dragging your new bike out of the garage. You typically only see motion at the beginning of a surveillance video, the rest of the one-minute footage normally shows nothing but motionless background (Figure 3).

Figure 2: Videos recorded by the camera are available for download.
Figure 3: Most frames only show the closed door.

Fast Forward to the Action

"Cut to the chase," people say when someone fails to come to the point. This probably refers to action films, where the audience does not want to see long-winded, suspense-building scenes but prefers to fast-forward to the car pursuit at the climax of the Hollywood production.

In this sense, it would be nice for the software to scour the video for frames in which a subject actually moves through the scene, so that the viewer knows whether the videos are worth watching and, if so, the location to which to fast forward in the video.

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Motion Detection

    The motion detector software, Motion, monitors the video signal from one or multiple cameras and is able to detect whether a significant part of the picture has changed, record and track movement, or launch arbitrary external commands to trigger other actions.

  • Blender 3D Animation

    Blender not only generates realistic single frames; it is also capable of capturing the natural movements of people and animals. We’ll introduce you to some of Blender’s animation features.

  • PhotoFilmStrip

    Easy-to-use PhotoFilmStrip produces high-quality videos and offers plenty of useful features.

  • PiCam Surveillance

    The new PiCam camera for the Raspberry Pi delivers image data with very little overhead, making it ideal for video surveillance applications. We find the bumps in the road you'll encounter and show you how to smooth them out with a few Linux commands and pipes.

  • Surveillance with NAS

    Take advantage of the low watt per operation compute power offered by modern NAS to monitor your cameras.

comments powered by Disqus

Direct Download

Read full article as PDF:

Price $2.95