Megapixel network cameras |
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A network camera that offers megapixel resolution uses a megapixel sensor to deliver an image that contains one million or more pixels. The more pixels a sensor has, the greater the potential it has for capturing finer details and for producing a higher quality image. Megapixel network cameras can be used to allow users to see more details (ideal for identification of people and objects) or to view a larger area of a scene. This benefit is an important consideration in video surveillance applications.
Megapixel resolution is one area in which network cameras excel over analog cameras. The maximum resolution a conventional analog camera can provide after the video signal has been digitized in a digital video recorder or a video encoder is D1, which is 720x480 pixels (NTSC) or 720x576 pixels (PAL). The D1 resolution corresponds to a maximum of 414,720 pixels or 0.4 megapixel. By comparison, a common megapixel format of 1280x1024 pixels gives a 1.3-megapixel resolution. This is more than 3 times the resolution that can be provided by analog CCTV cameras. Network cameras with 2-megapixel and 3-megapixel resolutions are also available, and even higher resolutions are expected in the future.
Megapixel resolution also provides a greater degree of flexibility in terms of being able to provide images with different aspect ratios. (Aspect ratio is the ratio of the width of an image to its height.) A conventional TV monitor displays an image with an aspect ratio of 4:3. Megapixel network cameras can offer the same ratio, in addition to others, such as 16:9. The advantage of a 16:9 aspect ratio is that unimportant details, usually located in the upper and lower part of a conventional-sized image, are not present and therefore, bandwidth and storage requirements can be reduced.
Suitable applications for megapixel network cameras Megapixel network cameras are excellent for many applications, for example when video with extreme image detail is required, such as in overview surveillance of banks, transportation hubs and other premises.
Some megapixel cameras offer “multi-view streaming”, which means that the same camera can deliver different video streams from different areas of a scene, which essentially leads to one megapixel camera replacing several standard cameras – for example, by monitoring more than one cashier in a retail store. Digital pan/tilt/zoom is another advantage offered by megapixel cameras.
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