RUNNING HDTV
Understanding HDTV
What is Digital Television or DTV?
Digital TVs are televisions that can receive and display digital television broadcasts sent using any one of three following categories: HDTV (High Definition TV), EDTV (Enhanced Digital TV), and SDTV (Standard Definition TV).
What is the Difference Between HDTV, EDTV, and SDTV?
HDTV, EDTV, and SDTV are three grades of televison or displays. They reference the maximum resolution capability of a digital television or display to fully display digital broadcasts without having to
Vertical Res.1 | Horizontal Res.2 Aspect Ratio3 | Scan Method4 | |
1080 lines | 1920 dots | 16:9 Wide | Interlaced |
720 lines | 1280 dots | 16:9 Wide | Progressive |
HDTV grade televisions and displays are capable of displaying a maximum of either 1080 lines using interlaced scan method or 720 lines using progressive scan method.
Vertical Res.1 | Horizontal Res.2Aspect Ratio3 | Scan Method4 | |
480 lines | 640 dots | 4:3 | Progressive |
EDTV grade televisions and displays are capable of displaying a maximum of 480 lines using progressive scan method. All resolutions higher than 480 lines must be reduced to 480 lines in order to be displayed. Progressive scan method reduces flicker; however, pic- ture quality may not necessarily outperform 480 interlaced when viewed at normal view- ing distances.
Vertical Res.1 | Horizontal Res.2Aspect Ratio3 | Scan Method4 | |
480 lines | 640 dots | 4:3 | Interlaced |
SDTV grade televisions and displays are capable of displaying a maximum of 480 lines using interlaced scan method. All resolutions higher than 480 lines must be reduced to 480 lines in order to be displayed.
1Vertical Resolution (Scan Lines)
Vertical scan lines refer to the number of horizontal lines a TV or display can display to create an image. As the number of lines increase, more information is displayed, resulting in better picture quality.
2Horizontal Resolution
Each horizontal line in a TV or display is made up of individual dots (pixels). The higher the number of pixels, the finer the TV picture becomes. Horizontal pixel measurements using today's technology can range from 250 for a VCR to as much as 500 for a DVD player.
3Aspect Ratio
Aspect ratio identifies the ratio of the TV screen's width over its height. A 16:9 aspect ratio refers to a wide- screen picture format, while a 4:3 refers to a standard “square” TV format.
4Scan Mode
Interlaced scanning is a method that creates a TV picture with alternating lines of information and is the cause for flickering. Progressive scanning is a method that creates a TV picture with consecutive lines of informa- tion that results in
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