Digital Video Motion Detection

If you've considered video motion detection in the past and passed it up, you might want to look again.


• Flying garbage. The first advantage of digital is multi-area coverage per scene. This reduces the area(s) that can be affected by outside stimuli. Although a small factor, it helps. And because we monitor the scene on a pixel-by-pixel basis, we can filter the images by object size, object direction, object color, object density, object motion and pattern, and object speed.
1) Object size. If I am looking for a man-sized target, then I have two size discriminations: larger and smaller. I do not want to see something the size of a car or truck. I do not want to see something the size of a squirrel or floating trash (unless it's the sports section of a really big newspaper). So, I have just eliminated or filtered out a good percentage of my potential false alarms.
2) Object direction. If I can tell my system to monitor, during specific time periods, only those objects that are moving east to west or up or down in the scene, then I again am lowering the affect of floating garbage or outside interferences. The garbage must now be of specific size, in a specific area of my scene, and moving in a specific direction at a specific time.
3) Object color. Although not a feature that you will find in the average, off-the-shelf DVMD, this would be a fairly easy and possibly effective algorithm to add to a good system. For instance, you sell John Deere® tractors, and you want to monitor visual activity in and out of your storage lot. You're not as interested in people as you are in equipment driving off. So, you set the filters for objects the size of your tractors, moving within a 50-foot area by the front gate, going away from the plant, and painted John Deere Green®. False alarms are becoming obsolete.
4) Object density. This is where your dust storm or fog comes into play. As long as I can see through the fog or dust at the percentage that I decide is acceptable, there will be no alarm. This is a good thought, but what about a person, dog, truck, fly or whatever moving between the camera and the object of protection? Let's go into a museum and protect a statue. A person walks in front of my statue and effectively blocks the majority of it from view of the camera, so an alarm is sounded.
About 16 years ago, I had the pleasure of doing some work in Australia. While there, I was approached by a friend that had a friend that was a modern dance director. Seems this dance director wanted to give his modern dancers the ability to create music through their motions on a stage. So he took two cameras, aimed them at the stage from opposing directions, and melded the two video signals into a computer program of his own design.
Using the same tactics of basic video motion detection, he was able to create multi-sized, invisible, three-dimensional cubes of air that were “hot.” He tied his multiple outputs to a sound synthesizer. The net result was that his modern dancers could float around the stage hitting different points and create their own music as they danced. The net result for the world of security was the birth of 3-D DVMD. Give me two or more opposing views of the same area, and I will give you one of the most advanced video motion detection features available today. Three-dimensional alarms detected and confirmed by multiple sources, simultaneously. This puts the bag on false alarms from one more perspective.
5) Object motion and pattern. We are now seeing systems that not only determine if an object is moving left or right, but also calculate its progress or pattern of movement. A floating piece of paper, regardless of size, does not move like a man walking. The cool part of this technology is that it is giving us the ability to tell the difference between a walking dog and a crawling man. Doesn't sound like much, but this is huge. Additionally, systems are being experimented with that read or predict an individual's intent based upon his actions when he enters a store or bank. Is he there to rob the place or do a general transaction? Does he demonstrate violent tendencies or is he of a passive nature? These systems are on the brink of introduction and will ultimately advance and change the direction of security's preventive nature. So cool!
6) Object speed. Somewhat self-explanatory. I want to detect motion but only if it is moving in a specific direction slower or faster than a predetermined speed. This could be used for various applications from parking lots to monitoring forklift drivers in sensitive, highly populated areas. We could use it for ticketing speeders on our highway systems, but the debates—oh, the debates.

• Animals. The above six filters also address the problem of small, flying, crawling, creeping animals and insects.

• Constant motion. This is one of the biggest, hardest, and yet most significant improvements in video motion detection since its inception. Almost 30 years of area protection have been slighted by fountains, rainstorms, snow, sleet and hail. How can I detect motion of an individual if the camera is auto-panning or it is snowing? We've discussed density as a form of filter, but snow and rain are different. They are not stagnant like fog. They are in motion, sometimes in several directions at the same time. A boat on the lake needs to be protected, but the waves make it move—heck, the wind makes it move. And what about all those ripples? Wouldn't all their sparkly indifference create false alarms? Absolutely. Hence the introduction of electronic semi-intelligence: the ability of a DVMD to learn a pattern or type or style of constant motion.
Now when the rain comes, the system continues to protect. It still sees the object of concern and filters out the mess between it and the camera. The boat is moving, but the system calculates its expected range and looks for the parameters of the defined threat. A fountain or escalator is in the middle of the image, but the system looks through the water or past the moving stairs and looks for change in the expected pattern of movement. It analyzes the change, and if it is beyond the acceptable parameters as defined by your filters, it creates an alarm. Man, oh man how I love the kinky thrills of modern technology. How I wish I could be here in 50 or 500 more years to look it over again.

What's It Cost?
OK, so what's the cost of this modern technology? It's not cheap. However, when you consider that we have the ability to replace or remove a huge array of various types of electronic alarm mechanisms—leaky coaxial, fence alarms, microwave motion detection, outdoor photo beams, infrared motion detection systems—the cost of the systems drop quickly.

If you considered video motion detection in the past and passed it up, start looking again. I think you will be amazed and pleased with what is available to you now.

Charlie Pierce is the President of LeapFrog Training & Consulting, a company dedicated to training the professionals of the CCTV industry. Visit its Web site at www.LTCTrainingCntr.com.