When looking around at the current, past and future state of CCTV systems as they relate to the digital revolution, one does not have to look too far, too long or too hard to see and realise that the camera has taken the next step in the process of evolution. I know, this is a statement of understatement. I know that the overall ignorance that is driving our industry is trying its best to ignore the technology of IP cameras. But the facts, the processes and the technology is proven, available, affordable and ready for your everyday applications.
Let us start with the IP. What are we talking about? IP stands for Internet Protocol. These are the digital cameras of our industry. So why not just call them digital cameras? A couple of reasons. Firstly, these cameras were originally developed (several years ago) to transmit their images via the Internet. Consequently, they were required to fit and conform to the protocol of the Internet.
Secondly, the manufacturers of analog CCTV cameras have been toting their hybrid, digitally enhanced analog cameras as digital cameras for so long that the meaning or definition of a digital camera is cloudy in most people's minds. So the consequence is to assign a specific name or title to your product that will stand out beyond the misnomers, myths and misunderstandings of an overall ignorant industry. Hence we have IP cameras which are the true, original, 100% digital cameras of our futures.
All right, we are ready and moving. IP cameras are starting to spring out of the dust and woodwork everywhere. And like their various counterparts, they are being toted by respective manufacturers as being the answer to all CCTV imaging problems. So, I will, through the next several hundred words, try to bring reality into focus before the industry gets carried away again.
First, not all IP cameras are created equal. Just like their analog counterparts, no one IP camera is right for all applications. There is nothing new to this philosophy. It is just that everywhere I look, people seem to be enamoured by the word digital. Somehow, being convinced that digital is magic and therefore a cure or cause of all woes. Bottom line - remember and design your application completely and then let the technology respond accordingly. You will find, just like everything else that we have been working with for the past 50 years, that only a few specific cameras will fit your needs. The one that fits might not even be digital.
Step one: when choosing a camera for a specific application, you must first determine the sensitivity required to produce an image. Inside, this is no challenge in most cases as we tend to have both natural and man-made light at our disposal. Under normal circumstances, even the minimum of interior lighting is more than enough for an average quality camera to work with.
Outside, we have many considerations . . . mostly related to the surrounding reflective surfaces that our camera will watch. Bottom line, this process of minimum sensitivity is the same for IP cameras as it has been for analog cameras over the past 50 years. Your camera, regardless of analog or digital base, must have the ability to work under the most stressful lighting conditions that your application most often provides. I have been working on a job lately that just screams for the use of DVD quality or Mega-pixel IP cameras. The problem? The night-time sensitivity calls for a unit that can work in sub-zero lighting. The only possible solution? Thermal imaging. Problem . . . or opportunity? Two cameras for the same situation - IP during dawn to dusk and thermal from dusk to dawn.
Step two: determine the minimum amount of resolution necessary to reproduce an image equivalent to the needs of your application. Here again, nothing has changed except for how we think and calculate. The need is still equal to the application. However, we no longer will speak in horizontal or vertical lines. We will now speak in reference to Common Intermediate Format (CIF) . . . squares of colour . . . digital pixels. The CIF resolution standard and definitions were driven by the DVR industry and align with the analog NTSC (480 lines) and PAL standards. The resolution ratings of all digital or IP cameras are multiples or divisions of CIF. Consequently, we are speaking about true grid resolution, the number of squares of colour that we have as based upon rows and columns. Our most common IP resolutions (to date) are as follows:
1. CIF = 352 x 240.
2. Quarter of CIF = (Q CIF) = 176 x 120.
3. 4 times CIF = (4 CIF) = 704 x 480.
4. 16 times CIF = (16 CIF) = 1280 x 1024.
To keep perspective, some of you have been listening to pixel resolution versus grid or CIF, so let us do the calculation in a different format - let us talk about pixel resolution. CIF = 352 x 240 = 84 480 kilopixel resolution (84,5 kpr). 4 CIF = 337,92 kpr 16 CIF (also referred to as HDTV 1024) = 1 310,72 mega-pixel resolution or 1,3 mpr. Word on the street has a 3 mpr IP camera coming to the industry before the end of the year. Continuing forward with perspective, those of you that have photographic digital cameras will be happy to know (or not) that a 4 megapixel image (2000 x 2000) is equal to 400 ASA film resolution and a 6 megapixel digital image is equal to 100 ASA film resolution. Our original digital standards were developed for the VGA monitors (video graphics association) at 640 x 480.
The first and biggest advantage of digital resolution is that it is ultimately unlimited. The first and biggest disadvantage of digital resolution is that a square of colour is a square of colour and therefore cannot be enlarged into sharper detail. It can only be enlarged into a larger square of colour.
So, if you fail to get the quality of the image that you required in the first place, there is little or nothing that can be done to improve it. The still standing problem with any high resolution image is that resolution equals frequency. Frequency equals bandwidth. Bandwidth is the mystical, missing link that all IT people are continuously trying to protect and horde religiously. However, digital is extremely flexible. I can make a digital image smaller in size while increasing the number of pixels per inch and in effect cut down the amount of storage space necessary to store the image or the size of the bandwidth needed to transmit the image, without giving up the detail. The advantage? Simple - high detail resolution, low impact bandwidth.
However, I cannot take a small, low pixel count image and improve it. So you will need to rethink how your final image will be impacted. The basic problem is that 50 years of training has taught us that increasing or decreasing the resolution in analog images does nothing to the actual raster size of the image. It always fills the screen. Digital images, on the other hand, change three ways with the increase or decrease of resolution.
1. The physical size of the image. Increase or decrease the amount of resolution and you ultimately change the raster size of the image in direct proportion. However, with digital, we do not necessarily have to change the raster size, but we can.
2. The actual size of the pixels (squares of colour). Increasing the resolution of an image increases the number of pixels describing the image. So, if the raster is fixed, the only response is to make more, smaller pixels in the same area. However, as stated above, in most cases the raster size will increase as well. So, you ultimately end up with a larger image, with more pixels that are smaller.
3. Smaller pixels (even though more pixels) in a smaller area (raster) requires less space to store an image or less bandwidth to transmit.
Unlike digital recorders, IP cameras are very flexible in the mode of delivery of the final image. The real advantage is that IP cameras start with a digital format and do not have to give it up or alter it into another format for the sake of compatibility. They can, but they do not have to.
Lastly, in our long line of 'take a look at this, the IP cameras come with a formidable amount of features that tend to make the average, digitally enhance analogue hybrid pale when compared. First, all IP cameras are 'plug-and-play'. Meaning, in simplest terms, that anyone with a PC, portable computer or PDA with a browser can plug an IP camera into the network and go to work. This, however, is the last common point between IP and analog cameras. Just like their analog counterparts, you can, according to your budget capabilities, purchase any level of quality of IP camera.
So let us look. The basic IP camera is just that - basic. It has two connections - power and Ethernet. This unit may or may not be fixed. It creates an image, for the most part at CIF or possibly 2 x CIF. But do not look for much more than this. Panasonic has a sexy little unit that has a fully functional mechanical pan/tilt with a zoom lens. Fully and truly a plug and play unit. However, it is a basic unit - no frills.
The next step above basic takes us to the first of the real IP security cameras. The most important difference in this step up is that these cameras are actual computer servers. What does this mean to you? Simple? Your world of options just opened wide. Need more bandwidth on you network? No problem. Create a new local area network (LAN) using your IP camera as the server. Actually, this is really cool, because it keeps your business network and your security network separate.
The next major difference that you will notice is the outputs of these IP cameras. You have BNC (for analog), 10/100 ETH and RS422 or RS232. In simplest terms, you now have the ability to transmit at two or more levels or formats simultaneously. This means that you do not have to convert your entire existing CCTV system to a digital format to take advantage of the IP camera features. The day will come (in the not so distant future) when you will have to convert your system, but not today. You can continue to use your coaxial cable for a while longer. Plug-and-play. Plug an IP camera into any system, new or old.
Looking a bit further, you will find that the first level IP camera has alarm input and output capabilities built into the camera. So what, you say? So, now you do not have to run a pair of wires all the way back to the main control point to have programmable triggers. You just connect your contact, photo-beam, mat or motion detection system outputs to your nearest camera. Obviously, this will save you wire and labour. But the true essence is that you do not have to have a command travel so far before being acted upon. Think about it. The average analog camera must send a continuous stream of video information back to the main control point to be acted upon. This takes up bandwidth. What if you put the alarm input at the camera and gave the camera a simple instruction to ignore all actions unless the alarm itself was tripped. Would not your bandwidth transmission requirements drop? Of course they would. "But," you say, "I need to see this image on a continuous basis." Okay each application calls for its own requirements. IP camera transmissions, as a rule, require less bandwidth than a standard analog camera. So watch a continuous video stream when you need to.
This brings us to another feature of many basic or mid level IP cameras. The ability to control or modulate how many images or how much resolution is sent each second from the camera.
Again, I refer to the analog camera. This unit will send a continuous stream of 60 fields, 30 frames per second at the cameras full resolution at all times, down a coaxial cable. What if you had the ability to set a camera's frame rate transmission? What if you were able to set a camera's standard, non-alarm resolution to a third of normal? Would not either one of these actions cut down on the bandwidth transmission and storage space requirements? Absolutely. This is where digital imaging steps out. With analog, we are always thinking in 2:1 ratios. This means two fields to create one frame or picture. NTSC = 60 fields/30 frames per second. PAL = 50 fields/25 frames per second. Digital does not work in 2:1 ratios. Therefore, ['realtime] digital video is 25 or 30 images per second. It depends what side of the world that you are on.
"But," you say, "from time to time, I need full resolution and/or a full 30 images per second." Okay, we can handle this situation is a multitude of ways. The first might be to give the operator or observer the ability to control the frame and resolution transmission rate upon command.
The second might be to set a trigger in place. Something simple like a door contact or a passive motion detector. We will then program or tell our camera that under normal circumstances only one image per minute is required or perhaps only one third of the resolution is required or both. But, when the trigger is tripped, full resolution at a full 30 images per second is required. The third possibility would be a combination of the first two. In the end, the overall situation is still far better than what is offered with the average analogue camera. The key difference is that you need to think and plan well in advance of the initial purchase, installation and/or expectation of the system. This is to ensure that you have all the benefits in place according to your current and future needs and wants.
Another fair advantage of the IP camera is simple accessibility. You have more than one person, in more than one department, in more than one province, in more than one country that require access to the same camera at the same time. No sweat. Jump on the LAN or WAN and bingo, free access by unlimited numbers of individuals according to password or system restrictions. I know what you are thinking at this point . . . that you can do the same thing with any analog camera pasted into a digital system. And you are right . . . provided that you have a proper analog to digital converter in place. Just remember what happens to your image quality when converting analog to digital. It will usually drop in resolution by as much as 25% or more. The whole key to any analog/digital system is to first convert the analog video signal to digital and then compress it to conserve bandwidth. The problem is first in the conversion and then in the compression. Once resolution, colour or both is removed, it cannot be replaced. So the average user has a converted analog image that is 2 inches by 2 inches on their screen. The slightest magnification of this converted, compressed analog image creates a 'blockhead' effect. This is not usually the case with IP cameras. The digital image that is available to multiple users is smaller in size, but higher in resolution and so expands quite nicely. This is because you basically end up with a smaller version of the same digital image that you started with.
The next level of IP cameras would be the megapixel cameras. Because of the huge numbers of very small pixels on the 2/3" format CCD, our options are once again doubled. The first and best of these options is digital pan/tilt and zoom. Any analog system can offer cameras on pan/tilts with big zoom lenses. This is nothing more than the addition of two electrical, mechanical devices under and in front of a camera. This is simply the addition of one or two more pieces of equipment that: (1) requires extra controlling equipment and wiring; (2) requires on-going, long-term maintenance; (3) restricts the number of observers and/or users to one at any given time; and (4) restricts the recorded image to whatever the camera is pointed at.
Bottom line, mechanical pan/tilt and zoom systems are about to be replaced in full. With digital pan/tilt and zoom, we take one, very high resolution camera (16 CIF - 1280 x 1024 or higher), and set it with a very wide angle lens (maybe 103°) and park it on a scene . . . say a parking lot. Now, the entire image is recorded at all times. However, any one . . . any number of any ones can now access this image, live or recorded, and play back only the portion(s) of the image that they find interesting. Because of the extreme detail of the resolution of the 2/3" CCD, those things that were out of reach in the past are now just a highlight away. It is really extremely impressive. You now have full pan/tilt options over the same range of area as before. You now have the same full zoom ratios that you are accustomed to. Key difference? Imagine 10 people working the same image, simultaneously with independent, full pan/tilt and zoom options and with no moving parts or extra cost of wiring or installation. Plug-and-play. Stick the camera up and go to the nearest PC, PDA or portable computer with a browser, and bang.
I realise that I have not even touched the surface of IP cameras on the upper levels. What are called the 'smart' cameras. This will come next time. Meanwhile, I can already hear the arguments about everything that I have already written. IP cameras are part of an unproven industry! Actually IP cameras have a longer history than two-thirds of the DVRs that are being sold. IP cameras are too expensive! Perhaps, but with a properly designed application, the average to the above average IP camera installation can usually be handled with a saving or at least a break-even minimum.
Bottom line folks. Buyer beware! Any technology is a potential money pit if not properly investigated and tested prior to purchase. I only point out what is already here and what all of you will be working with before the close of the decade in six more very short, very fast, very progressive years. Wake up and beware.
Charlie Pierce has been working in the security industry since 1974 and consults and speaks in the electronic security area internationally. He can be contacted at LeapFrog Training & Consulting (LTC), 091 563 322 6669, fax 091 563 336 8853, [email protected], http://www.ltctrainingcntr.com/</a>
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