About CCTV
based for decades, Closed Circuit Television (กล้องวงจรปิด CCTV) security systems กล้องวงจรปิด on a standard developed by the National Television System Committee (NTSC), which develops the image resolution limits, only 480 lines of vertical scanning. In other words, the image by scanning the scene was created from the top down to produce 480 lines of data. As you can imagine, this greatly the image quality for large scenes, which is typically limited to safety oversight.
A particularly disturbing aspect of the standard NTSC video was with an analysis of interlaced video. The interlaced scan is a two way process, located in the “foreign” lines in the video area, or captured in the first test, and the other “couple” lines have been cut, or caught in a second analysis. It was originally made to the appearance of the border “flashed” into the picture as a TV or monitor is updated. It is no longer necessary, monitored with the current technology. Although the resolution of interlaced scanning provides greater image in the post-it, you lose half the resolution and leads unwanted “combing” artifacts when subject is moving. This can be overwhelming for a monitoring system.
Recorders
Security applications often require video images to be stored for a long time and stored for retrieval. Until recently this was achieved with standard equipment, the recording on video tape. These methods require frequent change of tapes, restricts the ability to browse and retrieve video information at certain times, and suffered from long-term deterioration of the signal recorded on magnetic media.
A quantum leap in performance was achieved with the introduction of low-cost digital recording equipment for the end of 1990. As the technology evolved, the speed with which the digital data as part of the can be transferred necessary for the transmission of video images.
The development of IP video cameras in a position matched the following advantages for the monitoring of the safety of the industry:
* Resolution กล้องวงจรปิด IP CCTV cameras and multi-megapixel image quality of HDTV at 30 frames per second.
* IP-cameras with a progressive scan format, scan the image on its head in a single framework, making the effect of the above-described hair for the old interlaced NTSC video format.
* The cameras can be moved anywhere on an IP network (including wireless).
* Video, audio and Pan / Tilt and Zoom can be transmitted over a single CAT5 cable network.
* Live video can be accessed from any computer, anywhere, including through the Internet and many other mobile devices.
High definition video surveillance systems
Of course, almost immediately, the parallel development of the case with HDTV in the consumer market has been married for security and digital cameras, the new interface for IP CCTV.
High-definition video or high-definition video most often refers to devices with screen resolution 1280 x 720 pixels (720p) or 1920 x 1080 pixels (1080i/1080p). High Definition Video. HD cameras, surveillance cameras provide exceptional image quality in near or real-time video rates, and 16:9. With high-definition video images are clear and sharp, and are formatted for modern screens and monitors. HD cameras are ideal for surveillance applications, where you set priorities and pace of the picture quality.
Summary
have introduced only last year a number of manufacturers กล้องวงจร ปิด IP CCTV HD formats, for the security market. Manufacturers such as Toshiba, Sony, Panasonic, and Ganz, all carry a full line of high resolution, high definition IP surveillance cameras and accessories. The prices have declined rapidly and compete with older technologies, especially when taking into account the maintenance costs of equipment, as most systems can use existing CAT5 IP networks.
If you are a new security shopping there really no reason not to keep a system of surveillance cameras HD .first
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