What happens when you record every frame emitted by an IP-camera? You end up with too much data to make sense of. I now have nearly unlimited data storage, but have little interest in reviewing everything stored. Watching recorded footage in real-time is too time-consuming to be enjoyable, or even reasonable. While playing it back at 2x or 4x speed might sound like a good idea, that’s still a lot of video to look at.
Most video editing software offers a “scrubbing” operation for rapidly finding a point in time. Scrubbing is the act of manually moving the transport control backwards and forwards through the images. If you’ve ever scrubbed looking for a single frame you remember seeing, you’ll have noticed that it’s sometimes hard to find the frame. Your monitor is displaying no more than 60 or 75 frames per second: if you scrub over a time period with a resulting rate faster than this, you are not seeing everything.
“Video summarization” is a field of study aimed at developing algorithms and methods to help abstract and identify interesting features in a segment of video to help direct viewer’s attention. Here is a great quote describing video summarization [ 1 ].
Video summarization methods attempt to abstract the main occurrences, scenes, or objects in a clip in order to provide an easily interpreted synopsis.
At Sensr.net, we consider video summarization to be an important part of our technology, recognizing that keeping a collection of all the frames your camera emits is just too much data to use. Our summarization techniques are straightfoward: we use motion-detection algorithms and save only those frames. We also offer a simple form of “hierarchical video-summarization.” When you look at a shot of all of the hours-of-the-day you are presented with the most important 24 frames of that day. Similarly, the days-of-the-month are summarized by the most important frame of each day.
Sensr.net has been hard at work laying the “pipes” for moving the frames emitted by internet cameras through our processors and into the cloud. You can expect to see more from us in the video summarization arena. Until then, take a look at this excellent slide presentation and think about what sorts of summarization you would like to see for your internet camera application.
To the right of this article, you can see a streaming view of the DCS-920 from my house. This capability is enable by a new service from Sensr.net. The viewer is called a “widget” and can be plugged into any web-site or blog.
Viewer widgets can be created for any cameras that you own. First, add your DCS-920 to Sensr.net (shown here http://www.tsheffler.com/blog/?p=187). Then, select the “My Widgets” item from the pull-down menu. This will show you the HTML embed codes for the widget.
The rest is easy. Copy the HTML and paste it into your blog like I did here.
The Trendnet TV-IP110W is another camera that works great with Sensr. This one has a rock-solid WiFi implementation and we’ve been running it at the Sunfire offices. It’s available on Amazon today for $59.
A few weeks ago there were a series of automobile break-ins in my neighborhood. The break-ins all occurred in the mid-morning. It appeared that only loose change or the stray GPS was taken. The damage done to the cars cost more than any of the items stolen.
These types of crimes happen all the time in San Francisco. It only takes a few minutes to shatter a window and take a few items. Rarely is anyone around to see what happened. It’s even rarer that any evidence of the crime is collected.
As luck would have it, I’ve been running surveillance cameras looking out of my front window. One day, a break-in happened right next door. I checked the camera and hoped that I’d caught footage of the guy this time. As it turns out, I did!
In the first frame you see him walking toward the break-in location. (I’ve smudged his face to protect the innocent here.) In the second frame you can see him carrying a black bag that was later identified as one of the items stolen. (Note: The total amount of time elapsed is 4 minutes.)
We forwarded these photos to the police and the neighbors. The police commented that it’s not often a clear picture of someone is captured. It’s also gotten the neighborhood fired up about paying attention to who is coming and going.
A couple of the neighbors have purchased DCS-920 cameras and have signed up for Sensr. We are going to be building our own “Digital Neighborhood Watch” up here. We’re all on the look out for this guy and will call the cops if he is spotted. (He was spotted lurking around once, but still remains un-caught.)
I recently came across another site helping to catch Bad Guys. It is called crookstube.com. It’s a video-sharing site for survillance footage of crimes. Using it, you can look at crimes in your area and see if you can help catch the Bad Guys. Of course, sometimes it’s entertaining to watch especially stupid crooks just for the fun of it.
I think crookstube.com is a nice complement to Sensr. Sensr helps you manage your cameras and capture video and perhaps keep it private. Crookstupe is a place for sharing the video clips you want to share with a “Crimestoppers” audience. These two sites might make a great match.
Sensr is not CSI
It’s been interesting to gauge the expectations of some of the people introduced to Sensr and IP-surveillance. A lot of people have watched a lot of episodes of CSI and expect infinite resolution and image enhancement techniques that don’t really exist yet! No matter, the basic technology is here today and useful.