2015/1/7 1568
CCTV camera is front-end image capture device, TVL is used to refer the image definition of analog camera, such as 420TVL, 480TVL, 540TVL, 600TVL, 650TVL, 700TVL, 800TVL, etc.. Higher TVL means higher resolution. And for IP camera, we use pixel to refer the image definition, such as 0.3 mega pixel, 1 mega pixel, 1.3 mega pixel, 2 mega pixel, 3 mega pixel, 5 mega pixel, etc.. Higher the pixel is, better the image definition would be.
Digital Video Recorder is terminal-end video storage device, it also have different resolution to signify its video compressing quality, such as QCIF, CIF, HD1, D1(FCIF), 960H, etc., so on the security surveillance project, we need to choose the suitable DVR based on the camera definition. If we choose a 700TVL cameras matched for CIF DVR, definitely it would cause unnecessary waste. In addition, there’s transmission loss in actual use, so with the same definition level, the actual definition of the DVR is lower than the camera’s.
The DSP of analog camera also have Effective Pixel. IVision engineer make a summary for the definition comparison between the cameras and DVR&NVR:
|
Device |
TVL/Pixel |
Effective Pixel NTSC |
Effective Pixel PAL |
Total NTSC |
Total PAL |
|
Analog SONYCCD |
480TVL |
510H*492V |
500H*582V |
≈0.25 mega |
≈0.29 mega |
|
600TVL |
768*494 |
752*582 |
≈0.38 mega |
≈0.43 mega | |
|
700TVL |
976*494 |
976*582 |
≈0.48 mega |
≈0.56 mega | |
|
Analog SONY CMOS |
1000TVL |
1280*720 |
≈0.92 mega | ||
|
IP Camera and NVR |
720P |
1280*720 |
≈0.92 mega | ||
|
960P |
1280*960 |
≈1.23 mega | |||
|
1080P |
1920*1080 |
≈2.07 mega | |||
|
3MP |
2048×1536 |
≈3.14 mega | |||
|
5MP |
2592×1920 |
≈4.97 mega | |||
|
DVR and NVR |
QCIF |
176*144 |
≈0.026 mega | ||
|
CIF |
352*288 |
≈0.1 mega | |||
|
HD1 |
576*288 |
≈0.16 mega | |||
|
D1(FCIF) |
704*576 |
≈0.4 mega | |||
|
960H |
928*576 |
≈0.53 mega | |||
Maybe years ago, the high definition (HD) refer to mega pixel resolution, and now there’s Ultra HD which means ten mega pixel. And in the market, there is Full HD, which means the video image’s length and width ratio is 16L:9W, normally means 1920*1080. The “Full” character is specially refers to the “16:9” ratio, as in the early days, there is no unified standard, there are also other ratio like for example, 4:3. And The Full HD Monitor means not only the screen resolution support at least 1920*1080P resolution image display, but also the inner circuits can handle and output 1920*1080 image signal.
