What is HDTV?

HDTV stands for High Definition TV. Watching HDTV is about watching high-resolution picture quality. Current Astro broadcasts are in standard-definition TV (SDTV), which has about 400 visible lines of resolution. HDTV, on the other hand, offers up to 1,080 lines of resolution, which has approximately five times more detail than SD.

HDTV format such as 1080p has more pixel than conventional SDTV - PAL format

If you refer to the diagram above, it is akin to having two to four times the number of pixels to render the same image, which means that HDTV provides far more detailed images than SDTV.

There are currently two main HDTV resolution formats: 720p and 1080i. The numbers refer to the number of lines or horizontal resolution on the screen, while the letter suffixes refer to “interlaced” and “progressive” scanning of the picture. The native resolution for a 720p video source is 1,280 x 720 pixels and for 1080i, it is 1,920 x 1080 pixels.

There is also another standard called 1080p which is called True HDTV. The 1080p format is mainly used in Bluray discs and HD DVD. Normal video DVD is only 480p resolution (720 x 480 pixels).

Interlaced Picture. Picture from Star Online

In an interlaced picture, only half the picture resolution is displayed at any one time. Because they interchange so rapidly, the eye perceives it as a whole picture (see picture above). With progressive scan, all the lines in the picture are displayed simultaneously, resulting in a clearer, more defined picture.

Unlike standard television, HDTV resolutions are typically in a widescreen 16:9 aspect ratio, which makes it ideal for movies and today’s widescreen flat-panel TVs, most of which are HD compatible. Sound quality is also improved and, when available, is in full Dolby Digital 5.1-channel surround sound.