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Learning More about Megapixel IP Cameras
n the last few years, demand for digital megapixel cameras has exploded. The trend started in the late 1990s with consumer digital still cameras and started to gain traction in the surveillance industry in 2002 with megapixel IP network cameras. Today, millions of consumer digital still cameras and tens of thousands of megapixel network cameras are being used every day.
Digital Convenience and More
Initially, digital cameras, both consumer and security IP network cameras, were adopted because of their convenience. For the consumer market, it meant no more fumbling with film and the home PC made sharing pictures with family and friends quick and easy. With security cameras, the convenience of plugging a camera into your existing IP network and viewing it from anywhere in the world within minutes was immediately compelling. Interestingly though, the evolution of the consumer and security markets differ substantially when it comes to image quality. In the consumer market, picture quality was not a marketable advantage for digital over film because film cameras already had excellent resolution. In the security industry however, megapixel network cameras had a clear-cut image quality advantage from the start, since traditional coaxial-based CCTV cameras are limited to PAL/NTSC resolution.
Megapixel IP Cameras’ Image Quality Advantage
The picture quality advantages of megapixel network cameras benefited end-users in a couple of ways. In some applications, a mega-pixel network camera could cover the same area as a CCTV camera with an improved level of picture quality so you could actually identify people. We are all too familiar with images captured by CCTV systems where the quality was so poor little could be learned and often no positive identification possible. Megapixel network cameras solved this major disadvantage. For other applications, megapixel meant covering a much wider area than CCTV cameras. Comparing apples-to-apples, a one megapixel network camera can cover more than four times the area of a CCTV camera with the same resolution. This means you can replace four CCTV cameras with a single megapixel camera, or 10 CCTV cameras with one 3.1 megapixel camera. End-users embraced this new power and efficiency immediately and the migration from CCTV to megapixel network cameras has predictably accelerated. With no legitimate way to combat loss of market share and still remain profitable, some began misrepresenting megapixel cameras to discourage the rapid migration away from their technology.
Bandwidth Management & Network Management
Multi-megapixel IP video - is digital data that takes up bandwidth so bandwidth management is essential in designing a cost effective IP video system. The built-in intelligence of our IP cameras enables you to manage bandwidth in several ways.
Image Cropping – Traditional surveillance systems can only display 4:3 ratio images. If you are trying to view/record a wide field-of-view you often view/record lots of unwanted video, like the sky or foreground. our IP camera lets you “crop out” the unwanted portions of the image which means less bandwidth and longer storage capacity.
Bandwidth Throttle – With many IP video systems you can’t predict how much bandwidth it will use. Every IP camera allows you to limit how much bandwidth it will use so there are no surprises.
Storage Throttle –embedded Network Video Recording (NVR) software gives you control over how much storage each IP camera will use. This unique feature lets you use inexpensive network attached storage (NAS) or your existing server without worrying about using up too much disk-space. It also enables you to optimise your system, assigning more disk-space to IP camera cameras in higher activity areas.
Dynamic Resolution and Frame Rate - With the embedded Network Video Recording (NVR) software, you are able to switch from low resolution, low frame-rate rates to high resolution, high frame rates when events occur.
On-Camera Video Motion Detection – Each IP camera network camera includes sophisticated multi-zone pixel-based video motion detection. Most systems require you to stream the IP video to a central computer where motion detection occurs. This means you are streaming video over the network even when there is no motion, which limits the number of cameras you can put on the network. our IP camera has motion detection built-in to the camera so if there is no motion, you aren't using any bandwidth.
Fewer cameras on the network – our IP camera’s multi-megapixel resolution lets you replace many conventional cameras with a single IP camera. A single IP camera uses less bandwidth than you would use with multiple traditional cameras required to achieve the same coverage at the same resolution.
Digital Pan Tilt Zoom (DPTZ)
Every one of our IP cameras includes digital pan/tilt/zoom DPTZ. DPTZ was developed to address problems with traditional mechanical pan/tilt/zoom devices. Mechanical devices let users redirect the camera but only record what you are zoomed in on. This can be a problem when there is more than one subject in the scene or if nobody is controlling the camera.
our IP camera’s Digital Pan/Tilt/Zoom DPTZ lets you virtually move around a large image using a smaller viewing window. Since it is virtual, you can still record the entire scene in multi-megapixel resolution even though you may be digitally “zoomed in”. This means you never miss a thing.
DPTZ also saves bandwidth. In many cases you don’t need to view a multi-megapixel image when you are accessing video over a WAN or the internet. IQinVision’s DPTZ enables you to view a much smaller image that shows the entire field of view in a smaller window. If you see something that interests you, simply zoom digitally and our IP camera’s multi-megapixel resolution kicks in. As you zoom in, DPTZ introduces more detail so you don’t suffer the distortion typical with other products.
Progressive Scan: Better pictures when there is motion
Most traditional CCTV and IP cameras use interlaced CCD imagers. Interlaced cameras take two low-resolution pictures then stitch them together to create a higher resolution image. For still pictures this works well but when there is motion, the two pictures don’t always line up which leads to a jagged, blurry “tearing” effect. IP camera IP Video systems use progressive scan CMOS imagers that take multiple individual high-resolution images. Since there is no “stitching” the images captured are much clearer, even when there is motion.
Lower Power Consumption
Progressive Scan CMOS imagers use less power than traditional CCD imagers, this enables you to power IP camera IP Video systems at up to 328’ (100M) over the Ethernet. It also makes our IP camera an ideal solution where power consumption is critical, including battery, solar and wind powered applications.
Better Lens Selection
Progressive Scan CMOS multi-megapixel imagers utilise the latest in Infra-Red (IR) mirroring technology. Most traditional CCTV and IP cameras use IR filters that get hot in bright scenes and can burn the camera’s imager which destroys the camera. Until now the solution was to use mechanical auto-iris (dc-iris) lenses that have moving parts. IP camera multi-megapixel IP video systems use a dichroic mirror that reflects IR energy. It doesn’t get hot so you can use reliable, fixed-iris megapixel lenses.
Setting the Record Straight:
Megapixel network cameras can be less costly than CCTV cameras
There have been misrepresentations that megapixel network cameras cost more than CCTV cameras. The initial cost of a professional quality megapixel network camera may be higher than a CCTV camera. However, in a large majority of applications, the total cost of installing a system using megapixel network cameras is substantially lower, sometimes as much as 50% lower. If you are considering using a megapixel network camera as a one-for-one replacement of a CCTV camera, and there is no established IP network, mega-pixel may be more expensive than CCTV. But the only reason to even consider swapping one-for-one is because the CCTV camera cannot deliver the image quality you need. Put another way, a tricycle is indeed cheaper than a Ferrari, but if you need to go 200 mph, try doing it on that nice cheap tricycle.
Megapixel camera networks do not necessarily use more bandwidth and storage than CCTV cameras
While megapixel images are larger than CCTV images, but once again this is not an accurate or helpful comparison. If you want to replace CCTV cameras one-for-one with megapixel cameras, it is because the CCTV camera cannot deliver the image quality you demand, period! A more instructive and fair analysis is to compare the files sizes of four 704 x 480 CCTV cameras against a single 1280 x 1024 megapixel image. If all cameras are configured the same, with the same compression, and are looking at the same scene at the same time you will find that a megapixel network camera actually uses less bandwidth and storage than the CCTV cameras combined.
A CCTV camera with a good zoom lens will not deliver the same level of detail you get from a megapixel camera
The area you can cover with reasonable detail (enough to recognize a face or licence plate) does not depend on the lens, it depends on the number of pixels covering the scene. The best CCTV cameras have, at most, 704 x 480 pixels. As a general rule, 30 pixels/foot lets you recognize a face or read a license plate. So, the best CCTV camera can cover an area 23 feet wide (704/30) and 16 feet high (640/30), for a total of 368 ft2. Knowing that, you would need to select a lens that gives you, at most, a 23' wide field of view to get enough detail. Putting a wider lens on the camera will simply blur the image and putting a telephoto lens on the camera will get you a sharper picture but a much smaller coverage area.
Alternatively, a 1280 x 1024 megapixel camera lets you cover a 43' x 34' area or 1462 ft2 (4x the coverage of the CCTV camera). A 3.1 megapixel camera, at 2048 x 1536, can cover 3450 ft2, or almost 10x the coverage of the CCTV camera. The lens simply determines how far away you want that level of detail. A wide angle lens can get the detail very close to the camera and a telephoto lens can get the detail at a great distance from the camera, but neither gets you megapixel quality and area of coverage.
What’s the Right Technology for You?
How do you choose the right components to ensure you never miss a thing? First, determine how wide an area you want to cover. For instance, if you want to cover a 10,000 ft2 parking lot with license plate and/or facial detail, your choices are: 28 CCTV cameras, seven 1.3 megapixel cameras, or three 3.1 megapixel cameras. Next, determine the camera to object distance. This is critical for the selecting the right lens. Remember the lens does not increase the resolution of the camera, it simply defines where you are focusing. Once you select the right focal length of the lens make sure the lens matches the camera quality. A lens does not increase the resolution of a camera but the wrong lens can absolutely hurt the resolution of the camera so while a plastic lens may suffice for a CCTV camera, a megapixel camera needs a mega-pixel quality lens.
Finally, make sure to record at the image quality you want. Be careful of those who may show you a high resolution image to close the deal, but actually record images at a lower resolution to save on the amount of storage they have to provide.
While a balance needs to be struck between storage space and image quality, the cost of hard disk space keeps getting lower and lower, and ICU will ensure that the optimum balance is achieved for you.
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