Getting the most from an analog system

IP video is the "buzz" of the video surveillance industry, and it certainly does have a number of clear advantages. However, while the future is likely to be networked video, the present is most certainly analog. IP shipments may be growing at a breakneck speed, but they started from a very small number. The vast majority of today's video shipments and installed base is still analog.

Sure, it would be nice if we could jump to the latest technology, but for most of us, that is not possible. We have significant investments in the systems we have. In this environment, we will need to squeeze the most return out of the company's investment. Still, while a wholesale upgrade may not be in the cards, a few tweaks here and there can make a major difference in the value your system delivers.

What those tweaks might be depend on the system you have now, but in any case, replacing boxes - whether they are your cameras, recorders or monitors - involves little expensive labor or installation and can be a very affordable way to improve your system.

Upgrade the Cameras

Let's start with the most critical piece of your analog systems, the cameras. Today's analog cameras offer significant improvements over the cameras you would have installed even two or three years ago.

At the top of the list is likely to be improved resolution. Why so important? The whole point of a surveillance system is to capture events with enough clarity to see what is going on. Whether it is a camera on a front door that needs to capture clear images of faces, a camera over a point of sale that needs to see the denominations of bills going into the cash drawer, or a parking lot camera that needs to pick up license plates - if your camera starts out with a fuzzy image, there is nothing the rest of the system can do to improve it. Today's cameras can provide as much as 600 lines of resolution, where as five years ago, 480 lines was state-of-the-art.

Another area that has improved in contemporary cameras is light sensitivity. Today's cameras not only have better sensor technology, but also have improved features such as "sense up" (an automatic increase of exposure time under low-light conditions) to provide dramatically better low-light performance. A lower-cost version of the traditional true day/night - which most manufacturers call electronic day/night - offers better performance than your older cameras (although still not as good as true day/night) for a fraction of the cost. If you are trying to view or capture scenes after dark, indoors or out, replacing old cameras will likely make a dramatic improvement.

Noise reduction is another feature that has changed radically since you bought your last analog camera. First-generation noise-reduction systems filtered noise by averaging the pixels on a single frame, which helps reduce noise in a low-light image, but also reduces the sharpness of the video. Second-generation reduction algorithms averaged pixels between frames, which does a nice job of reducing noise but introduces a blur on any item in motion. Today's best cameras combine the two techniques in a clever way to achieve maximum noise reduction while minimizing the blur. The result is not only a much clearer low-light image, but also the lack of noise prevents DVRs from filling their hard disks prematurely because noise fools their compression by looking like a lot of motion. That's a fix with multiple benefits.

The Dynamic Range of a camera defines its ability to view both very bright and very dark objects at the same time. The need is best illustrated by the camera used in an office lobby - lots of bright windows and an entrance door with frequent pedestrian traffic. A camera purchased five years ago will not be able to see the details of the faces of people in the lobby while picking up the outside details through the windows or the faces of a visitor entering through the bright doorway. The latest Wide Dynamic Range cameras, on the other hand, capture clear images of the people inside and out.

You may also find that today's cameras feature a number of "problem-solver" features that would have been difficult or impossible to find five years ago. For example, take Digital Image Stabilization, a feature which removes the shake from an outdoor camera that gets buffeted in the wind. A number of cameras now have this feature as a standard menu option, and when needed, it dramatically improves the image quality by processing the video and locking the objects that are not supposed to move in one place.

Best of all, the cost of a good high-end analog camera has dropped close to 20 percent over the last five years, while gaining a dramatic level of functionality. If you have a limited budget, camera upgrades are a likely and simple place to start.

Upgrade the Monitors

So you replaced some of your cameras and you do not see much of a difference? Do not forget about the other weak link in the chain, your monitor. Yes monitors have improved as well. Beyond that, yours is likely not producing the same picture as it was the day you bought it. First, CRT monitors grow dimmer every day they are used, and 24-hour operation adds up quickly. LCD monitors up until very recently were illuminated with small florescent tubes (ccfl) which also dim with use. The loss of brightness is gradual and therefore hard to notice, but one look at a new monitor next to an old one tells the story. A dim monitor has a dramatic effect on image quality.

New monitors have also improved in resolution. A standard LCD monitor today has a native screen resolution of 1280x1024 pixels, which is a 67-percent increase over the LCDs of a few years ago, and a 3.5x increase over the CRTs we used for CCTV. While this greatly exceeds the capabilities of an analog camera, modern DVRs can use all of this new resolution to display multiple images on one screen. The quality of each individual video on a quad image will improve dramatically.

Also, do not forget that older monitors were generally connected to the DVR with a single analog "composite video" connection. When compared to the more modern VGA or even HDMI connections found on today's monitors and DVRs, the old connections produce a significantly poorer image - lower resolution and less sharpness.

Once again, the price of a good monitor has fallen dramatically, and most systems have only a few. This is another piece of your system where an inexpensive upgrade can make a major difference.

Upgrade the Recorders

There is one more link in the chain, and that is your DVRs. Here too, there have been changes that could enhance the performance of an analog system.

Most DVRs sold in the last few years record at CIF resolution (352x240 pixels) and typically at a frame rate of around 7 frames-per-second per camera for a 16-channel box. Since CIF resolution is about one-quarter of the resolution of a good analog camera, there is a lot of room for improvement. There are DVRs available today that will record full analog resolution (D1: 704x480 pixels) and do so at a full motion frame rate of 30 frames-per-second, if you need that speed.

The case for full resolution is easy to understand. Resolution and the width of the scene you wish to monitor go hand-in-hand. If you want to view a wide scene, for example a parking lot, and still view details, you need a lot of pixels or lines of resolution. How much? Well, a rule of thumb is 20 per foot is the minimum for general surveillance, while a clear view of faces requires 40-80 per foot. So, at CIF resolution, the number of lines/pixels of resolution is severely limited and that limits the width of the scene you can view and still see the details. In fact, with CIF, that width is a maximum of 17 feet and even then, you will not be able to read a license plate. If you want a clear view of faces with CIF resolution, you will have to zoom in to a scene width of no more than approximately 8-9 feet!

So, bottom line, an upgrade to your DVRs will enable you to either get a significant improvement in the quality of your existing camera views or the ability to zoom out for increased situational awareness. Either way, the move to D1 resolution is well worth the upgrade.

Of course higher resolution means more storage, but the good news here is that new DVRs use the latest SATA hard disk drives. These drives are not only available in very large sizes (as much as 2 terabytes of video) but are also available for some amazingly low price points. In fact, hard drive costs have dropped from $1.40 per GB five years ago to 7› per GB today. The cost of storage is less and less of an issue. Many vendors have DVRs today that support 6TB of storage. That will support 45 days of D1 recording on 16 channels at 7.5 fps at a cost far less than you paid for your five-year-old CIF DVR.

An Achievable Plan

In these tough economic times, there are many companies that simply will not consider an upgrade to a new IP video system. Still, you can achieve a significant upgrade to your CCTV surveillance without a complete system replacement. Start by thinking about which cameras in your system would really benefit from an update. You do not have to replace them all - start with the critical scenes that make the most difference. Then think about an update to your monitors - small money and a big difference.