The object must fill at least 5% of the frame in order to be distinguishable from other projects. One must be able to distinguish between a person or an object/overview image of what is happening in an area.
The object's height must be at least 10% of the image height. A video motion detction (VMD) system must be able to detect a movement/get a detailed overview of an area.
To recognize a person or an object the person or object must be at least 50% of the image height. One must be able to recognize a person or recognize a typical characteristic of a person.
To be able to identify a person on a TV screen the person must be represented in close-up and be 120% of the image height. The image must be so detail-rich that the person can be identified when one compares the video image with a photograph.
CCTV SURVEILLANCE DESIGN TIPS
The Purpose of Video Surveillance is to discourage criminals. but if a crime does take place it also makes it possible to establish the course of events and identify the people and objects involved. To Optimize the use of video surveillance system the following criteria should be met.
- There should be two types of cameras: wide-angle "overview" cameras and close-up-cameras.
- The number of wide-angle cameras and their placement should be sufficient to cover all the points of interest in the monitored area(s) with good image quality.
- There should be close-up-cameras whose placement and type should be such that they can provide detail-rich images with the right proportions. It is preferable that these images show both the whole body of the person(s) in the shot and closer head-and-shoulders shots as well. Appropriate places for close-up cameras would be at the cash register and the entrance.
- There should be enough light.
- There should be a set schedule and routines for regular system evaluations.
- There should be a documented action plan for what should be done if there is suspicion of criminal activity.
- Staff should be trained to operate the system correctly and given the opportunity to keep thier knowledge up to date.
- Recordings that show criminal activity must be handled in such a way that the original images can be handled over to the justice system in a manner that is in accordance with the