What is hdtv

What Is HDTV?

HDTV, or just HD (High-definition television) refers to video having resolution substantially higher than traditional television systems SDTV, or SD (standard-definition television). HD has one or two million pixels per frame, roughly five times that of SD.Early HDTV broadcasting used analog techniques, but today HDTV is digitally broadcast using video compression. Image resolution describes the detail an image holds. Higher resolution means more image detail. Early HDTV broadcasting used analog techniques, but today HDTV is digitally broadcast using video compression. Video compression refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compensation. Video compression is an example of the concept of source coding in Information theory. This article deals with its applications: compressed video can effectively reduce the bandwidth required to transmit video via terrestrial broadcast, via cable TV, or via satellite TV services. HDTV broadcast systems are identified with three major parameters:

• Frame size in pixels is defined as number of horizontal pixels ? number of vertical pixels, for example 1280 ? 720 or 1920 ? 1080. Often the number of horizontal pixels is implied from context and is omitted, as in the case of 720p and 1080p.

• Scanning system is identified with the letter P for progressive scanning or I for interlaced scanning.

• Frame rate is identified as number of video frames per second. For interlaced systems an alternative form of specifying number of fields per second is often used. HDTV has twice the linear resolution of standard-definition television (SDTV), showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.

What Is HD Ready?

HD Ready concerns the abilities of television receivers to display high-definition pictures. HD Ready televisions are capable of accepting and displaying a high-definition signal at either, 720p, 1080i or 1080p using a component video or digital input, but does not have a built-in HD-capable tuner.

Plasma television.

A plasma display panel (PDP) is a type of flat panel display common to large TV displays (80 cm or larger). Many tiny cells between just two panels of glass hold a mixture of noble gases. The gas in the cells is electrically turned into a plasma which emits ultraviolet light which then excites phosphors to emit visible light. HDTV plasma televisions usually have a resolution of 1,024?768 found on many 42 in plasma screens, 1,280?768, 1,366?768 found on 50 in, 60 in, and 65 in plasma screens, or 1,920?1,080 found in plasma screen sizes from 42 in to 103 in. These displays are usually progressive displays, with square pixels, and will up-scale their incoming standard-definition signals to match their native display resolution.

LCD TV Liquid-crystal display televisions.

LCD TVs are quickly displacing the only major competitors in the large-screen market, the plasma display panel and rear-projection television. Color on an LCD television is produced by filtering down a white source and then selectively shuttering the three primary colors relative to each other. The accuracy and quality of the resulting colors are dependent on the backlighting source and its ability to evenly produce white light. LED-backlit LCD television. The LEDs can come in two forms, Dynamic RGB LEDs which are positioned behind the panel, or white Edge-LEDs positioned around the rim of the screen which use a special diffusion panel to spread the light evenly behind the screen. LED-backlit LCD TVs differ from conventional CCFL-backlit LCD TVs in the following:

• They can produce an image with greater dynamic contrast compared with CCFL-backlit LCD TVs. • With Edge-LED lighting they can be extremely slim. Current models on the market can be approximately one inch thick.

• They can offer a wider color gamut, especially when RGB-LED backlighting is used. • Lesser environmental pollution on disposal.

• Higher cost due to current market product placement.

• Generally have a lower power consumption in the realm of 20-30%.

3D-ready TV.

3D television is a television that employs techniques of 3D presentation, such as stereoscopic capture, multi-view capture, or 2D plus depth, and a 3D display, a special viewing device to project a television program into a realistic three-dimensional field. The choice is yours!


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