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Resolution Revisited for HD Surveillance

The Development of High Resolution Video Systems

Although the term “high definition” has been used since the 1930’s in the HDTV industry, the precise meaning has changed considerably over the years as manufacturers competed to outdo each other. In the past three decades in the CCTV industry, the resolution of analog cameras and DVR systems was based on D1 or 4CIF (usually 480 TV lines in NTSC and 576 TV lines in PAL) used in the TV industry, and was also widely used in other video systems like VHS. Starting in the 1990’s, consumer products such as digital cameras and handheld DV recorders underwent a resolution evolution of sorts. In just one decade, the resolution of consumer products jumped from 1 megapixel (1280 x 1024) to over 10 megapixels. This trend influenced early IP CCTV camera development as well with the development of CMOS technology, and IP camera manufacturers started promoting IP cameras with higher and higher resolution, resulting in a resolution war in the industry.

More recently, thanks to the popularity of flat screen TVs and HD 720P / Full HD 1080P resolution, CCTV users have realized that whereas high megapixel resolution may help them while performing some special operations such as digital zoom, using IP cameras that provide resolution comparable to their display device (HD 720P / Full HD 1080P flat screen TV) is enough. For this reason, the race to achieve higher and higher resolutions has essentially ceased, and instead, HD 720P and Full HD 1080P IP cameras have become the mainstream in the IP CCTV industry.

The Impact of High Resolution on the Video Surveillance Market

Higher resolution cameras brought a lot of change to the design and use of CCTV systems, with users now expecting CCTV video to provide a higher level of detail and clearer image quality than before. For example, security personnel often need to be able to clearly identify persons or objects in a scene, such as at a point-of-sale monitoring site where each customer’s face must be clearly identifiable. Another important scenario is being able to identify the license plate on a vehicle, regardless of how fast the vehicle is moving. In these and other cases, using an HDTV or megapixel network camera will provide higher resolution images with more details than a non-megapixel network camera.

Higher resolution IP CCTV systems place a much bigger demand on bandwidth than lower resolution systems. A traditional D1 resolution analog camera with decent video compression requires 1 Mbps bandwidth to transmit full frame rate (30 FPS in NTSC and 25 FPS in PAL) video streaming, and a 1 megapixel IP camera requires 4 times the bandwidth, which comes to 4 Mbps. In this case, a system with 100 cameras would require 400 Mbps bandwidth to accommodate all of the required video streaming.

The conclusion of this simple calculation is clear: high megapixel IP cameras, especially those that support more than 2 megapixels, are difficult to implement in most real world environments without upgrading an existing system or sacrificing frame rate or image quality. People now realize that HD 720P and Full HD 1080P resolution strike an acceptable balance between the desire to achieve higher resolution and the load the higher resolution places on network bandwidth.

The Benefits of HDTV for IP Video Surveillance

After years of development, the current HDTV resolutions of HD 720P and Full HD 1080P have become the mainstream for IP CCTV cameras, and provide the following advantages compared to legacy analog systems or higher megapixel resolutions.

1. Better clarity compared to legacy analog systems

Legacy systems only provide up to D1 resolution, which is only 1/3 of HD 720P and 1/6 of Full HD 1080P. Consequently, with an HD IP camera users can see three times the clarity and image detail of a legacy analog CCTV camera.

2. Moderate bandwidth usage compared to higher megapixel resolution

HD 720P is approximately 1 megapixel whereas Full HD 1080P is approximately 2 megapixels, with both resolutions requiring moderate bandwidth for smooth video streaming compared to higher megapixel resolution IP cameras.

3. Synchronized with international TV standards

HDTV is the prevailing TV standard worldwide, and using IP cameras that support the same resolution guarantees you can get the most out of your camera and display monitor.

4. 16:9 aspect ratio

Megapixel systems have a 16:10 aspect ratio whereas HDTV has a 16:9 aspect ratio, and consequently IP cameras with HDTV resolution will ensure the fidelity of your video display.

The Next Generation of HD IP Surveillance

HDTV resolution has been widely recognized as the most suitable resolution for IP CCTV applications for most scenarios. Moxa’s IP surveillance solutions deliver HD (720p/1080p) image quality with low latency and bandwidth optimization for industrial video surveillance applications in extreme outdoor environments. Designed for a wide range of harsh weather conditions, Moxa’s new generation of extreme-weather IP cameras can perform reliably from -40 to 75°C without the need for a fan or heater, and offer many advanced features such as WDR (wide dynamic range), sense up, and 3DNR (3D digital noise reduction), to enhance image quality for applications in areas with low visibility.

Moxa’s 1080P 10x zoom IP camera can see the finest details with crisp, clear images.

Additional information about Moxa’s video surveillance solutions are available at the following links:

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