Thinking About Video Motion Detection?

Video motion detection (VMD) is rapidly changing how security professionals use video. The term "motion detection" as it is applied to digital video is ambiguous. It can refer to capabilities ranging from simple activity detection to the search of massive...

Advanced programming for "specific act recognition" is just beginning to emerge from development. This is motion detection that recognizes unique and complicated motions associated with undesirable acts or phenomena. Recognized acts can be the typical movement of shoplifters, acts of physical violence or phenomena such as fire. Video smoke detection programs are currently being marketed. Also emerging is the coupling of motion detection with character and biometric recognition. Systems that will spot a moving license plate or vehicle signage, process the number or characters remotely, and activate a response on a wanted vehicle should not be far in the future. Similarly, recognition of faces of note moving in a crowd will be finding their way to market.

Versatility of these systems continues to expand. Some systems can now learn new responsibilities by adjusting for the repetitive motions and routine activities. Other products are often capable of environmental adaptation, so as to be unaffected by changing light or weather conditions.

Virtually all advanced motion detection can be customized to some extent by the end-user. Programming can accommodate shifting operational requirements according to time of day, field of view, and changes in environmental motion. Most multi-camera, user-programmable systems permit the user to customize the visual response or the automatic response to any recognized movement pattern. The operator interface screens and devices can usually be modified standard computer operating system toolbox techniques.

What VMD Features Will Benefit My Application?
Applying the correct VMD equipment and features can solve numerous security challenges. The most important step, however, is not to look at the available equipment until gaining a thorough understanding of, and applying imagination to, the security and operational needs of the facility.

The security director, who understands his facility, and the design professional, who understands the options and applications, must begin by asking themselves the important questions: What can move? and What do we want to know about its movement? As simple as these questions appear, the answers must be detailed, accurate and complete.

The first objective is to identify what can move. This determines the surveillance areas to be covered by the cameras and begins to define the VMD product required. The answer to What can move? includes items of interest and any moving background items that may distract the system.

The items of interest can be items that are typically in motion and therefore either pass through the field of view, stop in the field of view, require identification, or must be followed by the surveillance apparatus. Some of these include:

  • Vehicles moving through entrances or on prescribed traffic routes.
  • Routine entry and exit of authorized personnel.
  • Baggage left unattended.
  • Personal property that is carried by the public.
  • Suspect individuals.
  • Employee work methods or handling of assets.

Conversely, the concern can be for items that are typically stationary and should not be moved. This is often applied to protecting critical or easily negotiable assets from theft or misuse. Items of interest may also be unusual circumstances or phenomena that are characterized by a particular motion. This list includes, but is not limited to:

  • Intruders or unauthorized personnel in an area or perimeter.
  • Leaks/mechanical failures.
  • Smoke, fire or flame.
  • Violent or erratic behavior.
  • Counter-flow directional movement.

Once the security director and the design professional have decided upon the items of interest, they must determine the best coverage areas and propose a layout. Often the location of the existing CCTV cameras provides a good starting point and the modifications can be minimal. Other times a completely new layout is necessary. The presence of background movement and environmental conditions can be a major consideration in the layout. As mentioned before, systems exist that can screen background movement and adapt to environmental changes. These capabilities, however, are not standard on many VMD systems, and should be specified by the design personnel if the layout determines that they are necessary.

Now that the type of movement is understood, the next criteria affecting design and selection should be what to do when the motion of interest occurs. If the item of interest requires immediate response, active surveillance personnel must receive the image and understand what they are seeing. Most motion detection has alarm states capable of seizing an active monitor. Many have enhancement graphics that will highlight the movement in question. This can be of enormous benefit to dispatchers communicating to responding personnel. If subject or object tracking is required, digital pan-tilt, mechanical pan-tilt, or panoramic cameras may need to be activated and under the control of the motion detection processor.