High Definition (or HD) provides a resolution that is substantially higher than that of standard-definition. This requires an HD television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (a.k.a. widescreen). Standard-definition television (SDTV) has usually a 4:3 aspect ratio.

 

High-definition television (HDTV) resolution is 1080 or 720 lines. In contrast, regular digital television (DTV) is 486 lines (upon which NTSC is based) or 576 lines (upon which PAL/SECAM are based).

To achieve true HD videoconferencing, it must achieve these standards:
•The bandwidth necessary to transmit the larger packets of data - typically 1 MB or above 
•A resolution and a frame rate (usually 30 fps) that is defined as HD (in descending order):

  • 1080p (1080 progressive scan lines)
  • 1080i (1080 interlaced lines)
  • 720p (720 progressive scan lines)

•An aspect ratio of 16:9 or widescreen (vs 4:3 aspect ratio with standard TVs)
•Visual equipment that will allow these HD resolutions be transmitted, with the available bandwidth necessary:

  • HDTV monitor (e.g. Plasma, LCD)
  • HD video camera and HD-capable codec