When capturing video in CCTV surveillance applications, there are three essential elements involved.
Camera:
Make sure the camera has the correct sensitivity for the application.
Sensitivity measures how the camera will respond to a certain level of light to obtain an acceptable picture. Sensitivity is typically measured in lux (1 lux = 1 lumen per square meter), with all camera manufacturers stating the minimum lux level needed to produce acceptable images. Camera manufacturers rarely explain where the minimum LUX level should be measured. Is it the minimum light on the scene, at the front of the lens, or on the camera image chip?
Lens:
The lens must match the camera for the proper amount of light to pass through it.
The lens aperture, or f-stop, determines how much light passes through it to the camera chip. The lower the f-stop, the more light the lens will pass. Many manufacturers will specify a certain f-stop lens with a specific camera. Using the lens specified will guarantee that the proper amount of light will pass through the lens, providing an adequate picture at a certain light level.
Illumination:
Unless we have light, we will have no video images from the camera. There are many sources of light. Some are good and some are not so good for CCTV surveillance.
1. Incandescent lamps - The bulb life is limited and these lights are very inefficient. The maintenance costs on this source of lighting are very high.
2. Fluorescent lamps - These lamps are more efficient than incandescent but still waste up to 60 % of the input energy to heat. These are commonly used indoors and are not used in outdoor applications.
3. High Intensity Discharge (HID) lamps - These are very good for CCTV applications due to their 60 – 80% efficiency and their ability to provide excellent color rendition. Low-pressure sodium is a form of HID lamp but is unsuitable for CCTV applications due to its yellow tinge. The best HID source in use today is metal halide. Metal halide bulbs provide cool white light and have excellent color rendition.
4. LEDs - LEDs are now considered to be the green solution to outdoor lighting. They are extremely efficient, and their reliability cannot be matched.
Thursday, May 21, 2009
Monday, May 11, 2009
Is H.264 Compression Becoming the Standard for Security Manufacturers?
Product managers and engineers constantly look for technologies that will shape the future security industry. We all agree that we need better image quality, faster transmission speeds, quicker emergency response times and improved storage efficiency. Most CCTV camera and DVR manufacturers now look to H.264 for the solution. Many of their data sheets now mention compression of H.264 as well as MPEG-4 and JPEG.
H.264 is simply an improved version of MPEG-4 with more efficient video compression technology. H.264 requires roughly half the storage space as MPEG-4. So what benefit does this provide for the end user? Since it is more efficient than MPEG-4, H.264 gives better image quality per bit of data. The system needs less bandwidth to transmit the video from IP camera to the network video recorder. That means it can be used on existing networks, cutting upgrade expenses. The end user can store more information on less hard drive capacity and lower installation costs.
As with any new technology, there may be some drawbacks. H.264 does require more processing power to decode the video. Manufacturers may utilize multiple processors to improve performance. Consider the cost versus the benefit.
When should you upgrade to H.264 technology? If a current system is only handling 6-7 cameras at 4-5 frames per second, 24 hours per day, H.264 may not be needed. If the existing system is not taking up much of its available storage space and the installed cameras are not streaming large amounts of data, H.264 is unnecessary. However, in systems with IP cameras, megapixel cameras or cameras requiring high framerates (like banking and casino applications), H.264 would definitely be a viable solution.
H.264 is simply an improved version of MPEG-4 with more efficient video compression technology. H.264 requires roughly half the storage space as MPEG-4. So what benefit does this provide for the end user? Since it is more efficient than MPEG-4, H.264 gives better image quality per bit of data. The system needs less bandwidth to transmit the video from IP camera to the network video recorder. That means it can be used on existing networks, cutting upgrade expenses. The end user can store more information on less hard drive capacity and lower installation costs.
As with any new technology, there may be some drawbacks. H.264 does require more processing power to decode the video. Manufacturers may utilize multiple processors to improve performance. Consider the cost versus the benefit.
When should you upgrade to H.264 technology? If a current system is only handling 6-7 cameras at 4-5 frames per second, 24 hours per day, H.264 may not be needed. If the existing system is not taking up much of its available storage space and the installed cameras are not streaming large amounts of data, H.264 is unnecessary. However, in systems with IP cameras, megapixel cameras or cameras requiring high framerates (like banking and casino applications), H.264 would definitely be a viable solution.
Friday, May 8, 2009
Sample security maintenance schedules
Daily maintenance:
1. Confirm there are no errors displaying on any of the DVRs.
2. Verify proper PTZ control on all movable cameras.
3. Create an operational log and make entries daily of any issues/problems which need to be addressed by on site personnel or the installing company.
Weekly maintenance:
1. Check all cameras for normal video.
2. Verify video is being recorded by performing a search for a specific period of time. Archive video from the DVR to a CD or DVD using the management software.
3. Check the satisfactory transmission of images to remote center (where applicable).
Monthly maintenance:
1. Clean all system monitor screens with appropriate glass cleaner.
2. Wipe down all head-end equipment with a dry, lint-free cloth to keep the equipment clean.
3. Ensure that the camera has a proper field of view and that fixed cameras have not been repositioned.
4. Verify the required retention rate by checking the oldest video saved on the DVRs.
Semiannual Maintenance Schedule:
1. Visually inspect all major CCTV components (including cabling and connections, where accessible) for signs of deterioration or damage.
2. Check and clean cameras, lenses and housings as necessary.
3. Clean (vacuum and dust) internal workings of DVR.
4. Check hard drives on all DVRs.
5. Perform software upgrades when available.
6. Test UPS.
1. Confirm there are no errors displaying on any of the DVRs.
2. Verify proper PTZ control on all movable cameras.
3. Create an operational log and make entries daily of any issues/problems which need to be addressed by on site personnel or the installing company.
Weekly maintenance:
1. Check all cameras for normal video.
2. Verify video is being recorded by performing a search for a specific period of time. Archive video from the DVR to a CD or DVD using the management software.
3. Check the satisfactory transmission of images to remote center (where applicable).
Monthly maintenance:
1. Clean all system monitor screens with appropriate glass cleaner.
2. Wipe down all head-end equipment with a dry, lint-free cloth to keep the equipment clean.
3. Ensure that the camera has a proper field of view and that fixed cameras have not been repositioned.
4. Verify the required retention rate by checking the oldest video saved on the DVRs.
Semiannual Maintenance Schedule:
1. Visually inspect all major CCTV components (including cabling and connections, where accessible) for signs of deterioration or damage.
2. Check and clean cameras, lenses and housings as necessary.
3. Clean (vacuum and dust) internal workings of DVR.
4. Check hard drives on all DVRs.
5. Perform software upgrades when available.
6. Test UPS.
Friday, May 1, 2009
Video Analytics
In today’s world, many schools and corporate accounts simply do not have the staff to monitor security screens 24/7. Some end users want to prevent crime before it happens. This is extremely difficult without constant human monitoring.
This is where video analytics enters the picture. If you want to keep people out of certain areas, or you want to know if students are loitering in the hallways instead of going to class, or you want to know if someone leaves an object behind, video analytics can provide this information.
Video analytics technology examines the video for specific behavior patterns. It can have a specific time period available to determine if someone is in a specific area too long, or it can tell if a car is going too fast in a speed zone. Some manufacturers have the analytics built into the encoder. Others have developed software to run on PCs to do the processing.
Video analytics has many names. One may hear it called smart CCTV, Intelligent Video Software (IVS), Video Content Analysis (VCA) or Intelligent Video Analysis (IVA). (It should not be confused with Video Motion Detection, which is mostly used to reduce data storage, but can alert operators of human presence in an unauthorized area.)
Having video analytics added to a system is like adding another security guard on staff. Some systems can send emails if certain behaviors are detected, and other systems will send out text messages to cell phones. The recording rate can be increased if a certain behavior is detected, and can trigger bringing up certain cameras to full screen view and other cameras playing back video seconds before the incident occurred.
The following link details one school application:
http://secprodonline.com/Articles/2009/01/06/Intelligence-helps-squeeze.aspx
This is where video analytics enters the picture. If you want to keep people out of certain areas, or you want to know if students are loitering in the hallways instead of going to class, or you want to know if someone leaves an object behind, video analytics can provide this information.
Video analytics technology examines the video for specific behavior patterns. It can have a specific time period available to determine if someone is in a specific area too long, or it can tell if a car is going too fast in a speed zone. Some manufacturers have the analytics built into the encoder. Others have developed software to run on PCs to do the processing.
Video analytics has many names. One may hear it called smart CCTV, Intelligent Video Software (IVS), Video Content Analysis (VCA) or Intelligent Video Analysis (IVA). (It should not be confused with Video Motion Detection, which is mostly used to reduce data storage, but can alert operators of human presence in an unauthorized area.)
Having video analytics added to a system is like adding another security guard on staff. Some systems can send emails if certain behaviors are detected, and other systems will send out text messages to cell phones. The recording rate can be increased if a certain behavior is detected, and can trigger bringing up certain cameras to full screen view and other cameras playing back video seconds before the incident occurred.
The following link details one school application:
http://secprodonline.com/Articles/2009/01/06/Intelligence-helps-squeeze.aspx
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