One of the common misconceptions is that DTV and HDTV are synonymous. While HDTV, or high definition TV, is DTV, or digital TV, not all DTV is HDTV. You can think of HDTV as a special kind of DTV or a subset of DTV.
DTV generally comes in one of three standard formats: 480p, 720p and 1080i.
480p
480p is short hand for progressive 480 line resolution. Progressive scan DVD players display images in this format. Standard Definition TV or SDTV broadcasts with 480i or 480 interlace. The "i" in 480i stands for interlaced passing which prints the image on the screen in two sets of lines: the odd numbered resolution lines first and then even numbered ones. The progressive scan 480p gives images a much more fluid, film-like look. While 480p represents only half the potential of HDTV technology, it is still a step up from SDTV's 480i resolution. Since 480p broadcasting requires less bandwidth, broadcasters have the option to provide multiple channels of programming, which means more options for the viewer.
480p is short hand for progressive 480 line resolution. Progressive scan DVD players display images in this format. Standard Definition TV or SDTV broadcasts with 480i or 480 interlace. The "i" in 480i stands for interlaced passing which prints the image on the screen in two sets of lines: the odd numbered resolution lines first and then even numbered ones. The progressive scan 480p gives images a much more fluid, film-like look. While 480p represents only half the potential of HDTV technology, it is still a step up from SDTV's 480i resolution. Since 480p broadcasting requires less bandwidth, broadcasters have the option to provide multiple channels of programming, which means more options for the viewer.
Pros and Cons: high quality progressive scan DTV broadcast, takes up the least amount of bandwidth. Image loses crispness on larger screens. 480p is not HDTV.
720p
Unlike 480p, 720p is a DTV format that is also considered a standard HDTV format. Because it has more lines of resolution (720 compared to 480) 720p provides a much sharper picture than 480p. With a higher resolution, 720p looks better than 480 on larger screens 32" and higher.
Unlike 480p, 720p is a DTV format that is also considered a standard HDTV format. Because it has more lines of resolution (720 compared to 480) 720p provides a much sharper picture than 480p. With a higher resolution, 720p looks better than 480 on larger screens 32" and higher.
Pros and Cons: high quality progressive scan HDTV broadcast, doesn't take up as much bandwidth as 1080i. Image still looks detailed and crisp on larger screens (32"+).
1080i
1080i is the most commonly used HDTV format and provides the highest quality image than all other DTV standards, however whether this image is that much better than 720p is debatable. Despite the better picture quality, the benefits of 1080i cannot be seen on screen sets below 32" simply because the extra lines provided by the 1080i format are not displayable on smaller screens.
1080i is the most commonly used HDTV format and provides the highest quality image than all other DTV standards, however whether this image is that much better than 720p is debatable. Despite the better picture quality, the benefits of 1080i cannot be seen on screen sets below 32" simply because the extra lines provided by the 1080i format are not displayable on smaller screens.
Pros and Cons: 1080i - highest quality HDTV broadcast standard. 1080i broadcasting takes up the most amount of bandwidth. Since most Plasma, LCD or DLP TV sets do not come in true 1080 resolution, the image is converted to 720p or 480p in order to be displayed, which reduces picture quality. 1080p is superior to 1080i but since so few TVs can display 1080p, it has yet to become an HDTV standard.
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