More on Analog vs. Digital

Recently we talked with ADT’s Dan Morrissey about the advantages of installing analog, IP-based digital and megapixel cameras for municipal public surveillance systems. Now that we’ve covered the advantages of each of these camera types, we asked Dan...


Recently we talked with ADT’s Dan Morrissey about the advantages of installing analog, IP-based digital and megapixel cameras for municipal public surveillance systems. Now that we’ve covered the advantages of each of these camera types, we asked Dan to explain more about the potential disadvantages of each:

Analog: Analog cameras are obviously an older, limited technology. Camera sensors have been “digital” for many years; however, video signal transmission and display technologies supporting them have still operated in an analog world. Established standards, although they ensure interoperability, have also slowed innovation and acceptance of newer sensor capabilities. Dedicated communications infrastructures to support the analog components have also been limiting, although these components can be brought into the digital realm through the use of special-purpose encoding devices. Hybrid- and network video recorders (NVR) can assist in the transition of this existing infrastructure by allowing both analog and digital network-based video communications from the camera (in the case of Hybrids), or pure network-based video communications (analog camera encoder to NVRs) to push the digital connection all the way back from the camera sensor. Although this approach may extend the life expectancy of existing analog cameras and technology, the addition of the encoder module(s) to place the video on the network results in a more expensive, less physically efficient camera installation.

Digital: Not all organizations have the buy-in or acceptance of IT and information security professionals to allow the movement of digital video across existing networks, due to the potential bandwidth and digital storage (hard drive space) increases required by digital video streams. Also, although there is an effort underway by several industry organizations, there is not currently a standard defined that will ensure interoperability between and among digital cameras and other system management components. The innovations and flexibility associated with these new sensors have also introduced a host of new parameters that can be configured for each camera and system. Get it wrong and you may not only have a sub-optimal image, your result may be worse than with “simplistic” analog cameras. To accommodate the complexity of these new video processing methods, and rapidly evolving ones such as video analytics at the edge (via a DSP chip on the camera), the need for more training and experience among technicians is critical to ensure the necessary support for the digital innovations is available. As well, greater focus on the part of manufacturers toward intelligent or automated configuration methods is likely to develop over time.

Megapixel: Megapixel cameras share many of the drawbacks of digital video, since most current models have been implemented to support the network environment. In particular, managing the volumes of video data involved in megapixel systems is critical and evolving, making it difficult to expect broad interoperability of system components. Knowledge and understanding of the design and implementation requirements for a successful megapixel project are not well-established in the industry and differ significantly from the considerations when using analog and digital NTSC-standard cameras.

A recent Security Dealer & Integrator roundtable shed more light on the future of video surveillance technology. -- PSW Staff