720p and 1080p explained

720p explained

720p is the shorthand name for a category of HDTV video modes. The number 720 stands for the 720 horizontal scan lines of display resolution (also known as 720 pixels of vertical resolution), while the letter p stands for progressive scan or non-interlaced.

Progressive scanning reduces the need to prevent flicker by filtering out fine details, so sharpness is much closer to 1080i than the number of scan lines would suggest. A 720p frame has about 1 million pixels. Compared to it, a 1080p frame has 2 million pixels so the amount of detail doubles. However in practice the difference between 1080p vs 720p is not as obvious as the one between standard definition vs high definition (480p vs 720p). For example a regular DVD isn’t even considered high definition because it is either 720×480 (NTSC) or 720×576 (PAL) but it looks much better than regular NTSC or PAL TV broadcasts and not as great as 720p. That being said, you do get more detail from 1080p than from any resolution if you have the “winning” formula for screen size, resolution and viewing distance – that is if you have the optimum conditions to get the most out of 1080p.

1080p explained:
The number 1080 represents 1,080 lines of vertical resolutions (1,080 horizontal scan lines), while the letter p stands for progressive scan (meaning the image is not interlaced). 1080p can be referred to as full HD or full high definition although 1080i is also “Full HD” (1920×1080 pixels). The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels. This creates a frame resolution of 1920×1080, or 2,073,600 pixels in total.

The only pure 1080p content comes from high definition DVDs like Blue Ray and HD DVD. Regular DVDs are way below that, having just 480p or 576p. You also get HD content from TV broadcasts but for now only 1080i and 720p. Basically 1080i offers pretty much the same amount of detail as 1080p but the quality of fast moving scenes is a bit inferior to 1080p. To understand this better read the 1080p vs 1080i guide. 720p content will of course look the same (or very similar) on a 1080p screen as it does on a 720p screen because what also matters is the content resolution not just the screen resolution.

Here is a sample with the difference between 720p and 1080p:

480i - Total image resolution 337,920 pixels

480p - Total image resolution 337,920 pixels

720p - Total image resolution 921,600 pixels (roughly equivalent to a 1 mega pixel camera)

1080i - Total image resolution 2,073,600 pixels (equivalent to a 2 mega pixel camera)

1080p - Total image resolution 2,073,600 pixels (equivalent to a 2 mega pixel camera)

More lines is nice but don't forget about the 'p' and 'i' in the 720p, 1080i and 1080p. The letter is an abbreviation for the type of scan the TV uses -- 'p' stands for progressive and 'i' stands for interlaced.

HD-TVI, HD-CVI, HD-SDI, HD-AHD, Analog & IP Camera

HD-TVI, HD-CVI, HD-SDI, AHD, Analog & IP Camera

Even we enter into digital era, analog surveillance technology doesn't stop its innovation. Besides the HD-SDI and HD-CVI (in house technology of Dahua), today the Hikvision and other camera manufacturers announce HD-TVI cameras release.  HD-TVI means High Definition Transport Video Interface,  HD-TVI is based on traditional coaxial cable for video and data transmission, it supports not only 720P/1080P video signal, but also including audio, data signal over long distance up to 500 meters.

At present, there are approximate 100 million coaxial cables are deployed for analog camera connection. In the next 3-5 years, they will be replaced with high definition camera. However, some users start to worry they have to rewire, re-install or add new network devices for upgrading. This group of users prefer the economical and easy solution to upgrade existing system to HD, rather than adopting the IP camera. In this context, the HD-SDI and HD-TVI technologies were born.

HD-TVI advantages

500 meters long range video transmission:-

As we know, HD-SDI and conventional analog solutions only has limited 100 meters video transmission. Additionally, the cost of HD-SDI equipment is more expensive. The HDTVI technology (HikVision) offers long range distance video transmission at 1080P/720P through coaxial cable.  The cost of HD-TVI products is very affordable, permit users upgrade the system with minimum investment. This makes HDTVI become a perfect solution to fit all analog surveillance applications. Furthermore, the new HDTVI technology support UTC function which can allow user to remotely control the OSD menu and PTZ control via coaxial cable. This means user can quickly install and adjust the camera without accessing the camera itself.

HDTVI Camera with CS 4mm lens

Analog high definition resolution at 720P/1080P:-

Similar to HD-CVI (in house technology from Dahua) and HD-SDI, the new HDTVI cameras can deliver real time 720P/1080P HD resolution video without video latency. The HDTVI DVRs support full time 720P/180P video recording and playback. Through using HDTVI compatible cameras and DVRs, user can setup a complete new HD analog surveillance system or easily upgrade the existing conventional analog system to HD surveillance system.

HDTVI Camera with CS 12mm lens,

Broad manufacturers to offer great compatibility:-

HDTVI equipment is HDTVI open standard, which guarantees trouble-free connection to other HDTVI-compliant cameras and DVRs. By the way, the new designed HDTVI DVR also can support traditional standard video camera for offering great flexibility.  All HDTVI HD cameras can access third party DVRs equipped with HDTVI technology from other manufacturers. The main HDTVI members including TVT, Hikvision, Hisharp, Unifore, LSVT...etc.

HD-TVI vs Analog

In summary, the advantage of HD-TVI compared with Analogue is:

1.       HD resolution on 720P/1080P at 25/30fps

2.       Long distance transmission for HD video

3.       No video quality loss and delay for transmission

HD-TVI vs HD-CVI 

Obviously, HD-TVI and HD-CVI have very similar features, both of them can provide analog high definition solutions. HD-TVI derives from American based company that does not supply to only one manufacturer. Therefore we are expecting many analog camera manufacturers will release wide range of HD-TVI based cameras to market. Therefore, HD-TVI is more likely to become an industry standard, not a proprietary technology/solution.

HD-SDI vs HD-CVI 

HD-TVI vs HD-SDI 

In conclusion, compared with HD-SDI, new HD solution with advantages of:

1.       Longer video transmission distance up to 1000ft (300m) over regular coaxial cable

2.       700ft (200m) distance for video transmission over UTP (Cat5, twisted cable)

3.       More cheaper price for analog HD system

4.       Support twisted cable installation

HD-TVI vs IP Camera

Hence, compared with IPC, the advantages of HD-TVI are

1.       No network bandwidth requirement/influence

2.       No network configuration, as easy as analog system

3.       No video quality loss and compression

4.       No video latency issue, real time live-view

5.       Long video transmission distance

6.       More affordable price for camera and video storage devices

AHD advantages

A new kind of camera: AHD Camera (Analog high definition)/HD-AHD is developing so soon in the market now.
The price is similar as Analog camera and the image effect is similar as digital camera!

The Advantages of AHD Camera:
1) AHD Camera can link with general DVR and the resolution is looks like 1000tvl analog cameras.
2) AHD Camera can link with AHD DVR, and the resolution is Megapixel High Definition ( Now have 1MP, 1.3MP already).
3) Transmit by Coaxial cable-500m!!
4) The price is similar as Analog system no matter considering DVR or camera.

HD-CVI cameras vs HD-AHD cameras

1.       1.0 megapixel AHD camera adopts OV9712 + NVP2431H solution (CMOS Chip: OV9712 & DSP Chips : Nextchip NVP2431H), while HD-CVI camera adopts the PO3100K + DH9801 solution. In addition to the difference of solution, the price vary greatly, OV9712 + NVP2431 of AHD camera module only costs US$7.5, and PO3100K + DH9801 camera module costs approximate US$11.

2.       AHD camera can connect to CRT display directly, the image can display properly. HD-CVI camera connects to traditional CRT, it doesn't show images. For video live view/recording/playback, HD-CVI cameras need to work with HD-CVI DVR. It seems, the HD-AHD cameras support 960H output mode, which is very convenient for test and installation. Since the AHD cameras can be backward compatible with all traditional analog equipment. Compared with HD-CVI, it has advantages of great compatibility.

3.       Competiable with normal D1 / 960H, and analog peripherals (including distributors, matrix, etc.). Switch AHD, IP and Anolog video signal from AHD DVR in no time.

4.       Strong anti-interference capability & solid interface protection that can avoid space high frequency electromagnetic radiation to ensure a constant signal transmission of high definition video display without problems as frame drop and lock loss occurred.

Visit: HD-SDI High Definition CCTV vs Traditional CCTV Cameras