Showing posts with label megapixel. Show all posts
Showing posts with label megapixel. Show all posts

Wednesday, August 12, 2009

Megapixels and CCTV

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The word pixel is derived from ‘pix’ (picture) and ‘el’ (element) and is the smallest item of information within an image. Digital images are made up of thousands of these tiny, tile-like picture elements that each records a specific intensity of a single primary color of light (red, green or blue). The more pixels the image has, the higher the image resolution will be. A megapixel (one million pixels) is the term used to describe a large number of pixels in an image, or the number of image sensor elements in a digital camera or the number of display elements in a digital display.

High Definition (HD) is a type of megapixel camera; it’s just that HD is one specific type of megapixel camera in the megapixel family. For example, HD is limited to a maximum resolution of 2.1 megapixels; it has a slower frame rate and an aspect ratio of 16:9. HD is wonderful for certain applications and other types of megapixel cameras offer many more formats, aspect ratios and pixel numbers for other applications.

More and more security professionals are seeing the true value of integrating these high-resolution megapixel surveillance cameras into the existing systems monitoring their facilities. With higher resolution, the camera images are clean and clear which eliminates the need for overlapping camera coverage of areas, reducing the number of cameras needed to cover a single area and generally providing a better overall situational awareness. Combining megapixel cameras with other specialized cameras (such as thermal image, IR or P/T/Z) creates a system that is very effective, reliable, and cost-efficient.

These cameras are definitely a must in applications where details are critical for identification purposes; banks, airports, government facilities and other high-security areas, and also retail locations requiring point-of-sale monitoring are all good examples. With the high resolution and greater image detail, the security personnel can zoom in on specific portions of the recorded, or live, scene to identify objects, individuals or license plate numbers. Megapixel surveillance cameras can cover a wider area with exceptional detail; these cameras can provide detailed information that would be impossible to make out with a standard analog CCTV camera.

If you are concerned with megapixel cameras eating up your DVR/NVR hard drive space – worry not! Megapixel surveillance cameras only take up a little more hard drive space on your NVR/DVR that a standard security camera would.

Transmitting megapixel images via IP also requires a little more bandwidth than a standard analog CCTV camera; however you can minimize this increase by using the 16:9 aspect ratio (unavailable from analog cameras) which eliminates the upper and lower portion of the scene, parts that usually contain unimportant details, thus lowering the amount of bandwidth and storage space taken up by useless data.

Megapixel network cameras have a very important role to play in video surveillance applications, although they are more suited for one location over another, these cameras are easily integrated into existing installations, easily added to new proposals for installations, they are easy to use, they are cost-effective and they provide superior image quality when crystal-clear images are an absolute must.


~The WTI Team



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WTI (Wireless Technology, Inc.)

Video Surveillance Products Dedicated to the Broadcast, Global Security and Transportation Markets!

www.gotowti.com ● www.wirelesstech.com

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Wednesday, March 18, 2009

Decision: Analog or Megapixel?

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Megapixel cameras have come a long way in the last few years. Many articles and technical documents reflect a general consensus that the future will be all megapixel cameras.

This is indeed the latest trend and a very likely future… a distant future.

Analog cameras have been around much longer and have a distinct maturity in product offerings. This is seen in variety as well as initial cost to purchase and install. Analog has a proven track record of reliability along with a very large and established install base. This install base reflects an investment that most are not willing to part with until the life of the unit has run its course and the time has come for it to be replaced.

Granted: IP based video systems are here and consideration of network integration for video surveillance and services is a must. Megapixel camera technology is still developing and growing. However, to maintain the existing video investment, many will implement an encoder at the analog video camera to create an IP based camera. Many will simply change the DVR to create an IP based access point for all the analog cameras.

Megapixel or analog is not a choice that needs to be made for the entire system.

The beauty of the megapixel camera trend at the edge of the video network is that it does give more choices in coverage and surveillance options when building new or enhancing an existing video system.

There is a definite place for megapixel cameras in many (and most) surveillance installations. The decision for this should be considered on a camera-by-camera basis with specific regard for what is being monitored, recorded, and recalled for viewing or video evidence purpose.

The general market still indicates analog to be the predominant camera of choice (reference Summary section on page 8 of Analog vs. IP Cameras):

http://www.aventuratechnologies.com/newsletter/DOCS/Aventura_Newsletter_02_Analog_vs_IP_Cameras.pdf

In repeat of a previous blog…
Be it a completely new video network or an update/extension/replacement of an existing video network, the end result that balances function, finance, video coverage, and video storage/recall will very likely be a hybrid video system which contains BOTH analog cameras and megapixel IP cameras.

** Try this live outdoor analog camera connected to an encoder **
http://www.gotowti.com/Info/WTI_SidewinderInternetDemo09.pdf



The following reading is recommended before deciding analog or megapixel:

1.) Choosing Analog or IP Camera Systems for Video Surveillance (CCTV) theCgisite.com (overview of considerations needed to make decision on a camera-by-camera basis):
http://www.thecgisite.com/detail/choosing-analog-or-ip-camera-systems-for-video-surveillance-cctv-35.html

2.) Megapixel Video for D.U.M.I.E.S. – Part 1 of 4 Security Sales & Integration (good coverage of megapixel video technology):
http://www.securitysales.com/resources/SS3dumies.pdf

3.) The difference between HD and megapixel surveillance cameras IP Security Watch (insightful perspective for 2009 HD versus megapixel):
http://www.ipsecuritywatch.com/web/online/IPSW-News/The-difference-between-HD-and-megapixel-surveillance-cameras/512$14934

4.) Megapixel Resolution Comparison Chart PULS Global (basic spec comparisons of megapixel cameras from a camera distributor):
http://www.puls-global.com/megapixel-cctv.htm

5.) The Truth about Megapixel Network Camera Technology Security International (perspective from a megapixel manufacturer):
http://www.security-int.com/categories/megapixel-network-camera-technology/the-truth-about-megapixel-network-camera-technology.asp

~David Scales, Chief Technology Officer