Vision Docs - All your documents in one place

Now available on the app!

Imaging & Vision Handbook More

Improve your level of machine vision know how

BETTER TO KNOW MORE

Benefit from the expert´s knowledge

Vision Docs - Handbook available now

VISION EXPERTISE

AT YOUR FINGERTIPS

Get the Imaging & Vision Handbook! More

PAL

Phase Alternating Line

Standard used for colour TV in Germany and other countries of Western Europe, India, China and some countries of the Middle East. Compared with the US NTSC standard, PAL boasts a far greater stability of the colour component.

In the PAL standard, an image comprises 576 lines of 768 pixel siege. The 25 frames per second with an aspect ratio of 4:3 are divided into even and odd lines and transmitted as 50 fields (interlacing). This means that at the same data rate, the picture frequency appears to be doubled to the human eye and flicker is reduced. Interleaving of the brightness component and the colour component means that only one line or transmission channel is required for transmitting a PAL signal (composite video).

In imaging and machine vision, both 1-CCD colour cameras and 3-CCD colour cameras compliant with European standards output a PAL signal, although in this field the demands of image quality mean that better quality signals (Y/C, RGB) are generally used for further processing.

Technical features

  • Number of lines: 625 lines
  • Vertical frequency: 50 Hz
  • Horizontal frequency: 15.625 kHz
  • Video bandwidth: 5.0 MHz
  • Colour subcarrier frequency: 4.433618 MHz