Network cameras, also called IP cameras, are cameras with an IP network connection. The main components of a network camera include a lens, an image sensor, one or several processors, and memory. The processors are used for image processing, compression, video analysis and networking functionalities. Captured video is transported over an IP network via network switches and is recorded to a PC server with video management software.
Generally, network cameras can be classified in terms of whether they are designed for indoor use only or for indoor and outdoor use.
An outdoor camera requires an external, protective housing unless the camera design already incorporates a protective enclosure. Outdoor network cameras often have an auto iris lens to regulate that the amount of light the image sensor is exposed. Outdoor cameras offer more durable and weather resistant enclosures, with components designed to capture wider views and appropriate to outdoor lighting conditions.
Network cameras, whether for indoor or outdoor use, can be further categorized into fixed, fixed dome, PTZ, speed dome, and Day & Night network cameras.
In Fixed cameras the viewing angle is fixed and it is permanently mounted to monitor a specific area always. Because the camera and its direction of coverage are also pretty visible to everyone, in some cases, it can deter vandalism and crimes. Fixed cameras can be installed in housings designed for indoor or outdoor installation.
With Fixed Dome cameras, mostly designed for indoor surveillance, are fixed in a small dome type housing to cover a certain area always. Fixed dome network cameras are also weather and vandal resistant and hence suitable for outdoor applications. With a 3-axis mechanism, images can remain in an upright orientation when it is installed either against the wall or on the ceiling.
Compared with fixed dome type, a speed dome camera is integrated with pan, tilt and zoom capabilities, enabling a far greater field of view. With these abilities, a speed dome camera is mainly used for professional applications, such as airports, banks or city security.
A PTZ Camera refers to Pan/tilt/zoom camera where the camera's view can be remotely controlled either manually or automatically for tilting up and down, panning side to side and zooming in and out.
A Non-Mechanical PTZ camera can zoom in to any part of the image with no mechanical movement but by using wide angle lens and megapixel sensor. But here, the pan, tilt and zoom actions are limited.
Day/night cameras compensate for varying light conditions to allow the camera to capture images. As light reduces below a certain level, the camera can automatically switch to night mode to make use of near infrared (IR) light to deliver high-quality, black and white images.
Source : articlesbase.com
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