B.Sc. Multimedia ComputingMedia Technologies

High Definition Television

Agenda

Historical Perspective Comparisons with Traditional TV Basic Specifications of HD Equipment Viewing HD Broadcasting Receiving HD

B.Sc. Multimedia ComputingMedia Technologies

Historical Perspective

Traditional TV 405 then 625

405 Lines 625 Lines Where lines is the number of vertical lines of

resolution

Each line contains picture information

More lines means more information =

sharper pictures

HDTV Lines

Two formats: 1280 x 720 1920 x 1080

Thus HDTV can have up to 1080 vertical lines 1080p means progressive scan - non interlaced 1080i where I stands for interlaced - more flicker True HD is marketed as 1080p

B.Sc. Multimedia ComputingMedia Technologies

More pixels available with HDTV

Also higher definition through wider range of colour gradation

Similar comparisons as the differences between 35mm and medium format photography

Or a 1MB camera compared with a 4MB camera

B.Sc. Multimedia ComputingMedia Technologies

Comparative Resolutions

HD Specifications

PAL 4:3

HDTV 16:9

Comparative Aspect Ratios

HDTV Types

Integrated HDTV - or simply, HDTV; DTV with an Internal (built-in) High Definition TV Receiver.

Digital-HDTV-‘Capable’ or 'Ready'- Digital TV that is able to display HDTV - but with the addition of an external HDTV Receiver.

Display Types CRT (Cathode Ray Tube): Traditional TV Technology –

The established standard for television displays; best overall value picture quality and cost; major drawback is bulk and mass as size increases.

Plasma Display - Ultra-thin design, High Contrast Ratings, 'Fixed Pixel' Display; Size up to 60+ inches; some display limitations – costly, high burn-in risk; picture quality affected by inability to display black-colour; displays are extremely heavy and fragile; picture quality lost as pixels fade; many plasma displays do not display HDTV resolutions. Development continues.

LCD - Liquid Crystal Display; Thin design, size limitations; good computer monitor; sharp picture for static displays; problems displaying images in motion; many LCD Displays are not HDTV capable. Development continues.

Picture Viewing Methods

Direct-view – Images displayed directly on the picture tube (as in the traditional CRT – Cathode Ray Tube) or one of the new, alternative technologies with a “fixed pixel” screen; ie: LCD (Liquid Crystal Display); Limited Display Size – maximum range, about 40-inches.

Smaller screen sizes, (less than about 34-inches) are less effective for HDTV

Picture Viewing Methods

RPT - 'Rear Projection TV' – uses multiple, miniature picture tubes, (commonly 3) or pixel display, and a combination of mirrors and lenses to project the image from behind, on to the viewing screen; enables displayed picture to be significantly larger; size ranges: 43 to 70+ inches). Offers best value – picture size and quality at lowest cost.

FPT - 'Front Projection TV' – Projects images forward, to an external screen; more commonly used in Home Theatre Systems for displaying DVD Movies; for DTV/HDTV may require purchasing TV components separately – including, TV Receiver, A/V Receiver, Display Screen and Speaker System. Complete Systems can be extremely costly, and may require professional installation.

Enables an almost unlimited display size.

B.Sc. Multimedia ComputingMedia Technologies

Rear Projection

B.Sc. Multimedia ComputingMedia Technologies

Front Projection

B.Sc. Multimedia ComputingMedia Technologies

Receiving HDTV

Receiving HDTV

Receive HD Signals via broadcaster HDTV with built in decoder HD Ready TV and additional receiver Display Screen

Plasma TFT

Games consoles support HD signals - Xbox 360 and Playstation 3 (not Ninteno Wii)