960H Uncut: Understanding the Difference

 

New sensors, more horizontal pixels

960H refers to a new class of advanced imaging sensors that provide the highest levels of image quality available for the PAL and NTSC standards. These sensors serve as the bridge between standard resolution and high definition solutions. Ideal for capturing fine scene details, they are capable of capturing images that are 976 pixels wide with 30 percent higher resolution than previous generation analog 760H sensors.

Resolution through a standard

Vertical Resolution is independent of the system bandwidth and is defined as the ability of the system to resolve horizontal lines. This resolution is expressed as the number of distinct horizontal scanning lines, alternately back and white, that can be satisfactorily resolved on a television screen.

The standards used for analog video are PAL (625 lines), NTSC (535 lines) and SECAM (625 lines). However, not all of the scanning lines are used to display the image. Using PAL as an example, of the 625 available horizontal lines, 49 are used for blanking which result s in a maximum Vertical Resolution of 576 horizontal lines.

  Effective Pixels
Sensor PAL NTSC
960H CCD 976 (H) x 582 (V)
Approx. 570,000 pixels
976 (H) x 494 (V)
Approx. 480,000 pixels
760H CCD 752 (H) x 582 (V)
Approx. 440,000 pixels
768 (H) x 494 (V)
Approx. 380,000 pixels

 
 
 

Switching to horizontal

Horizontal Resolution is defined in the display technology world as the number of pixels across the screen. For video source application such as CCTV this is expressed in a slightly different manner as the number of alternating black and white vertical lines that can be resolved per picture height – and referred to as television lines (TVL)

To determine the effective horizontal resolution for a given sensor, simply divide the number of horizontal pixels by the aspect ratio:

horizontal pixels / aspect ratio = maximum horizontal resolution

Using this formula we arrive at a resolution of 720TVL for a 960H CCD sensor:

960 / (4:3) = 720 TVL

This calculation determines the absolute maximum resolution a monochrome camera with 960 horizontal pixels could theoretically achieve. However, the color filter of a CCD camera uses a portion of this overall resolution detect color differences. As such, with the best known color separation algorithms a 960H camera can achieve a luminance resolution of 650 TVL.

Similarly, 760H camera has maximum 570TVL of horizontal resolution in monochrome mode, with a luminance resolution of 540TVL.

  960H Sensor 760H Sensor
Raw image sensor resolution 720TVL 570TVL
Effective resolution (color) ~650TVL ~540TVL

Get the most out of 960H

960H sensors deliver crisp, clear video at the highest resolution available for analog systems and also offer extraordinary performance in low light. With an increased pixel count and an image that is 30 percent wider, every frame contains more information and more detail. The wider frame also delivers true-to-life images that let you get the full benefit of the latest widescreen monitors – unlike 4CIF or 760H sensors, there is no distortion or image stretching with 960H sensors.

With minimal additional cost for improved picture quality, 960H solutions are Ideal for anyone who wants ultra-high resolution analog technology. To fully realize the benefit of this exceptional image quality requires a complete end-to-end 960H system solution. Up to now these necessary system components have been rare. But with 960H DVR’s and high resolution monitors that support 720TVL becoming widely available, now is the time to consider upgrading your surveillance solutions.