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KEEPING UP WITH HIGH DEFINITION
Nov 1, 2001 12:00 PM By CHARLIE R. PIERCE No matter what you call it ¡ª pixels, grids, horizontal lines or vertical mass ¡ª it still boils down to resolution. How much do you have? How much do you need? Can more be added? Will there be more in the near future? Will there be enough for everyone? In the end, resolution is nothing more than a number. It is a digit we apply to an image to explain the amount of detail within it. Ask yourself a simple question: How defined is the picture I am looking at? Believe it or not, it's probably about the same amount today as it was 15 years ago. However, the definition of the picture is probably much better than it was five years ago. In the past few years, we have finally begun producing CCD cameras, recorders and monitors with resolution as good as their tube counterparts of 15 years ago. The problem is we have pretty much reached our peak under the current NTSC and PAL standards. These are the two most popular broadcast standards in the world, and they dictate just how much bandwidth an image can use. Bandwidth relates directly to resolution ¡ª the more of one you have, the more of the other there is. It's been a fairly well-known guideline: If you want to see the toys and tools of the future of CCTV industry, you should look at the current consumer industry. Recently, what was nearly a five-year time gap from adaptation of technology in one market to the other has dropped to less than two. So, using the current consumer market as a barometer, it seems the NTSC and PAL broadcast formats are about to be replaced by high-density television (HDTV) after NTSC and PAL's 50-plus years of dedicated service. Get ready, because we are all just a few short steps away from brand-new televisions in our homes. At the very least, we could be required to attach converter boxes to our ancient televisions that will knock the resolution of the broadcast HDTV image back down to NTSC (525 vertical lines) or PAL (625 vertical lines) levels. Here we are in the world of CCTV. We're excited about 400-plus horizontal line playback (0.5 million pixels). Meanwhile, the consumer industry is producing 4.2 million pixel resolution images (1000 +/- horizontal line res) from the same CCD formats. A 4.2 million pixel image is huge. It's HDTV. It's the holy mackerel, all rolled up in a neat package. But it isn't coming to the CCTV market for a while. Soon, my fellow fans, but not just yet. It may take three to seven more years (how's that for narrowing it down). Slowly, seriously improved resolution will become a seriously improved issue within our industry. Cost and compatibility with existing technology, however, remain important issues. The bottom line is simple ¡ª camera technology is currently advancing, at a really quick clip. It's so quick, in fact, that the idea of a CCTV camera being able to replicate and/or exceed the capabilities of the human eye is no longer a dusty dream. But for now, resolution seems to be taking a back seat because of NTSC and PAL broadcast standards. We need to be careful not to become too involved in keeping track of all of the new storage toys and innovations. We can't let our manufacturers step back 10 years and tell us that hugely improved resolution is not important to the industrial CCTV world. In other words, just because something isn't cost-effective today, we should not drop the ball for the near future. Where does that leave us? How about smack dab in the middle of a technology revolution? Sure, digital storage systems are all the rage. But they are also being temporarily held at bay by analog recording systems, thanks to price drops, known stability, and, let's not forget, less-scary technical jargon to wade through during a simple purchase. This will continue for at least another year, maybe two. However, on the sidelines we are redefining the CCTV camera to become more than a glorified picture-taking machine. Just a few years ago, we judged a camera based on its ability to provide a quality image in lower light. Of course, the lower light level, better-resolution images are still important, but they have become an almost everyday event. Today, we are categorizing our cameras into three different groups, and, for the most part, the groups have nothing to do with light levels.
There are more groups of cameras, and I have only opened the door just a bit. High resolution from a camera is no longer a problem. But high-resolution storage and high-resolution transmission are a different ball game. But we are, at least, on the field. Don't get into a big rush, because you should verify, test, prove and watch your designs and purchases carefully. Keep in mind however, that we truly do live in the time of imagination ¡ª both within the mind of the purchaser and the seller. So, remember, it's buyer beware! Charlie R. Pierce, president of LRC Electronics, Davenport, Iowa, is a leading authority on CCTV and a regular contributor to Access Control & Security Systems. |
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