HD Glossary
Learn about HDTV, one word at a time.
ATSC: Acronym for "Advanced Television Systems Committee," an organization developing voluntary standards for digital television.
Analog TV: Analog TV has been used to transmit conventional TV signals to consumers for many years. This method uses amplitude and frequency modulation of a radio transmission carrier.
Aspect Ratio: A numerical expression of the relationship of width to height. 4:3 refers to the aspect ratio of a conventional TV screen with the ratio of 4-unit width to 3-unit height, regardless of the actual size of the screen. 16:9 is the usual aspect ratio of wide-screen DTV formats, including HDTV.
Compression: The reduction of the size of digital data files by removing redundant and/or non-critical information.
Dolby Digital™: An audio compression technology that can deliver high-quality digital audio for up to 5.1 discrete channels. Also referred to as AC-3. For more information, go to www.dolby.com.
DTV: Acronym for "digital television." A technology for transmitting and receiving broadcast TV signals. DTV encompasses high-definition TV, standard-definition TV and other applications, including datacasting, multicasting and interactivity transmitted in digital form.
HDTV: Acronym for "high-definition television." HDTV provides significantly improved picture quality with more visible detail than standard-definition television. Typically broadcasts in a wide-screen format (16:9 aspect ratio) and may be accompanied by digital surround-sound capability.
Letterbox: Image of a wide-screen picture on a standard 4:3 aspect ratio television screen, typically with black bars above and below.
NTSC: Acronym for "National Television Systems Committee" and the name of the analog color TV format used in the US.
Pixel: Term used for "picture element." A pixel is a tiny sample of video information. Those are the little dots that make up the overall TV picture.
Resolution: The density of lines (vertical resolution) and dots (horizontal resolution) per line that make up a visual image. The higher the numbers, the sharper and more detailed the picture.
Scanning: There are 2 types of scanning modes — Interlace Scanning and Progressive Scanning.
SDTV: Acronym for "standard-definition television." A general term applied to conventional analog TV or DTV modes with 480 lines of vertical resolution.
Video Interconnect: The input/output of a video device. There are various connections available. Below is a summary of the options, ranked in order of overall connection quality. Some of these options may not come standard with all HD equipment purchases.
Analog TV: Analog TV has been used to transmit conventional TV signals to consumers for many years. This method uses amplitude and frequency modulation of a radio transmission carrier.
Aspect Ratio: A numerical expression of the relationship of width to height. 4:3 refers to the aspect ratio of a conventional TV screen with the ratio of 4-unit width to 3-unit height, regardless of the actual size of the screen. 16:9 is the usual aspect ratio of wide-screen DTV formats, including HDTV.
Compression: The reduction of the size of digital data files by removing redundant and/or non-critical information.
Dolby Digital™: An audio compression technology that can deliver high-quality digital audio for up to 5.1 discrete channels. Also referred to as AC-3. For more information, go to www.dolby.com.
DTV: Acronym for "digital television." A technology for transmitting and receiving broadcast TV signals. DTV encompasses high-definition TV, standard-definition TV and other applications, including datacasting, multicasting and interactivity transmitted in digital form.
HDTV: Acronym for "high-definition television." HDTV provides significantly improved picture quality with more visible detail than standard-definition television. Typically broadcasts in a wide-screen format (16:9 aspect ratio) and may be accompanied by digital surround-sound capability.
Letterbox: Image of a wide-screen picture on a standard 4:3 aspect ratio television screen, typically with black bars above and below.
NTSC: Acronym for "National Television Systems Committee" and the name of the analog color TV format used in the US.
Pixel: Term used for "picture element." A pixel is a tiny sample of video information. Those are the little dots that make up the overall TV picture.
Resolution: The density of lines (vertical resolution) and dots (horizontal resolution) per line that make up a visual image. The higher the numbers, the sharper and more detailed the picture.
Scanning: There are 2 types of scanning modes — Interlace Scanning and Progressive Scanning.
- Interlace Scanning
Interlace scanning requires two fields to transmit and display a frame of video. The first field displays the odd lines; the second field displays the even lines. The fields are aligned and timed so the human eye blends the two fields together and sees them as one. Examples of interlace scanning include the 1080i and 480i formats.
- Progressive Scanning
Process by which horizontal lines are scanned in succession, like reading lines of text on a page. An example of progressive scanning is the 720p format.
SDTV: Acronym for "standard-definition television." A general term applied to conventional analog TV or DTV modes with 480 lines of vertical resolution.
Video Interconnect: The input/output of a video device. There are various connections available. Below is a summary of the options, ranked in order of overall connection quality. Some of these options may not come standard with all HD equipment purchases.
- HDMI™: Acronym for "High Definition Multimedia Interface." HDMI is a trademark of HDMI Licensing LLC and was created as a digital interface standard for the consumer electronics market. The HDMI protocol combines high-definition video, standard-definition video, multi-channel audio and inter-component control in a single digital interface. For more information, go to www.hdmi.org.
- DVI™: Acronym for "Digital Video Interface." DVI is a trademark of the Digital Display Working Group. DVI only maintains its quality up to 20 feet of cable. For more information, go to www.ddwg.org.
- Component Video: There are two classifications of component video: HD and SD. Each uses a three-jack cluster of wires with the ends color coded red, green and blue. For each type listed below, the output of one device has to be of the same type as the input of another device (for example, if the output of a receiver is Y Pb Pr, the input of the TV must be Y Pb Pr).
HD: There are 2 types: Y Pb Pr and RGB.
SD: There are 2 types: Y Cb Cr and RGB.
- S-Video: Originally called "Super Video." When introduced, it was considered superior in quality to RF. This format separates luminance (black and white) from chrominance (color).
- Video (NTSC): Traditional video connection that is typically a yellow RCA cable. This format is a composite of luminance and chrominance.
- RF: The most basic video feed commonly associated with older TVs and VCRs. A coaxial cable feeds the TV signal, and is typically on channel 3 or 4.