HD READY?
Megapixel cameras offer a number of benefits, not least the ability to zoom in on your subject without compromising image quality. But, as Security Middle East reports, the high costs involved means that high definition technology currently only suits the more specialist applications
The term ‘megapixel’ is increasingly used as shorthand now to describe cameras which deliver higher-than-usual image definition.
To be more accurate, a megapixel camera is any model which produces images made up of more than a million pixels – as compared to the average picture from a good quality composite 540 TV line camera, which is composed of 440,000 pixels.
As ever, advances in the mass consumer market are helping to make possible affordable developments in the specialist security sector. We have reached the stage where even basic digital cameras sold at retail deliver five megapixels or more, and high definition camcorders becoming ever more affordable.
There are obvious disadvantages to working with higher pixel densities: the image files are larger and demand more memory from your transmission and storage systems. But there are clear advantages too: most attractively, there is more room for digital zoom to be used on these higher definition images before degradation becomes apparent.
This means there may be significant benefits in using higher definition images for certain applications – for example, by extending the zoom range you may be able to reduce the number of cameras needed to cover a particular area. One obvious application would be in viewing external areas and perimeters: captured images can be zoomed, panned or tilted digitally. Or it may be that you want to capture greater detail in a scene, in order to be able to analyse more closely what you are recording.
However although you may be able to reduce the number of cameras that you need, the cost benefit of doing this will probably be cancelledout by the additional cost of using megapixel devices. It is not just the cameras that are more expensive; you also need to use a higher quality megapixel lens and, not surprisingly, these usually cost more.
In addition you will almost certainly need a dedicated transmission infrastructure because the bandwidth required to carry 1Mb images will be too much for most standard corporate networks. You may also need to upgrade your monitors and your recording and processing equipment.
Megapixel options
Axis offers a number of megapixel network cameras designed to deliver crisp and clear video images, perfect for the identification of objects and persons. The range includes megapixel network cameras offering audio support, day-and-night functionality, and wireless transmission.
Claimed to be the smallest wireless megapixel network camera in the world, the AXIS 207MW offers resolutions up to 1.3 megapixel and both wireless IEEE 802.11g and Ethernet network interfaces. It provides simultaneous Motion JPEG and MPEG-4 streams and is designed for securing small businesses, residences and other remote indoor locations.
The AXIS 211M offers simultaneous Motion JPEG and MPEG-4 in full 1.3 megapixel resolution. With Power over Ethernet, two-way audio, and comprehensive network capabilities including IPv6 support, it is suitable for a wide range of installations. Axis also offers day/night megapixel models and fixed dome megapixel models.
Offering a high definition performance of 15 times average resolution, the Ganz C-MP5P 5 megapixel camera from CBC offers a number of advantages of the kind described above. It can zoom in to give greater definition of sensitive locations and allow forensic examination of areas of the image that would be, with other cameras, unrecognisable. An IP model it can stream video up to 2560 x 1600 resolution and be powered over the network or via a separate 12V dc supply.
An excellent example of a day/night model is the Ganz C-MP3P, which features two megapixel sensors. During the day a 3 megapixel colour sensor operates, whilst a 1.3 megapixel monochrome sensor takes over when light falls.
Both these models are designed to work best with Megapixel lenses such as those in Computar range, which are available in a range of focal lengths and angles of view. The wide-aperture (F1.4) design of these lenses allows them to achieve clear images in low light conditions. By reducing distortion and improving illumination uniformity over the CD, they also provide better recognition accuracy.
Bosch has introduced a new range of megapixel cameras for use with both hybrid and digital video systems. The Bosch Megapixel products aim to offer ultra high-resolution digital imaging and more system flexibility. Delivering up to 3.1 million pixels in each image, the cameras are said to provide sharp video that captures details that some cameras miss.
There are three models within the new range, including the entrylevel NWC-0700 model that uses a two-megapixel sensor to deliver colour images. At the higher end, the 3.1 megapixel NWC-0800 is said to give extra-fine definition, allowing small details to be observed from further away. Both models offer almost seven times the number of pixels found in conventional high-resolution CCTV systems.
Dedicated Micros has launched a new rapidly deployable IP CCTV camera designed to deliver consistent two megapixel image capture over wide areas. Based around its NetVu Connected architecture, the CamVu 2000 aims to support seamless communication with other NetVu CCTV elements. The company claims that this allows deep
integration with a wide range of DVRs and devices whilst supporting simplified integration with larger systems.
And Aviglon has released a rapid deployment kit that it claims can be set up to deliver 16 megapixel surveillance footage in under ten minutes. The High Definition Rapid Deployment Kit (RDK) is designed for public safety applications and to meet the temporary surveillance requirements of police, private investigators and transport authorities.
In conclusion
Megapixel camera technology which is feeding in from the consumer market offers exciting potential for security planners and has reached the point, now, where it can deliver significantly superior images and allow much greater interrogation of pictures.
But the cameras will not work in isolation: every element of any high definition CCTV system has to be upgraded to handle the increased data density.
So at the moment this remains a fantastic solution for specialist applications such as street-scene monitoring with local recording, for high security installations, and for users able to make investments well above average. It is also an increasingly attractive option for applications where images are recorded on-site, where the main objective is to gather high quality video evidence for investigative purposes and where transmission is not a problem or where high frame-rates are not needed.
 The Bosch megapixel range aim to offer ultra-high image definition and system flexibility
|