Usually refers to a video format consisting of either 720 active lines of progressive video or 1080 active lines of either progressive or interlaced video.
Digital broadcasts with either 1,080 active scan lines in interlaced format (1,080i) or 720 lines in progressive format (720p) as defined by the Advanced Television Systems Committee. (See active scan lines, ATSC, and interlaced scanning.)
High definition in projectors relates to the quality of the image the higher the resolution (number of lines that make up the width and the number of lines that make up the height), the better the image quality. Projectors tend to use 1024 * 576, 854 * 480 and 1280 * 720. a resolution of 1280 * 720 would normally be found on more expensive projectors and is a High Definition image.
There are many digital video HD formats all of which exceed the NTSC 720x486 frame format. Some display progressive scan instead of interlaced frames. Many use a wide screen 16:9 aspect ratio.
A new type of free, over-the-air TV broadcasting with up to six times the picture detail (resolution) of conventional, Standard Definition broadcasting. The National Association of Broadcasters reports that 885 television stations are broadcasting a digital TV signal and that 60 network TV series are being broadcast in High Definition.
Video signals in tv sets or similar items which have a better image quality than standard definition. All used HDTV formats use the aspect ratio 16:9.
High Definition is a Canadian radio program, which debuted on February 4, 2006 on the CBC Radio One network.