High-definition television (HDTV) refers to a television or video system that offers a significantly higher image resolution than previous generations of television technologies, such as standard-definition television (SDTV). This increased resolution results in a clearer, more detailed picture with less flicker and better rendering of fast motion.
Key characteristics of HDTV include:
* Higher Resolution HDTV provides a greater number of pixels on the screen, leading to a sharper and more detailed image. While SDTV typically has a resolution of 720x480 pixels, HDTV starts at 1280x720 pixels and can go up to 1920x1080 pixels. For instance, a 1080i HDTV signal can have six times the resolution of a 480i SDTV signal.
* Widescreen Aspect Ratio HDTV typically features a 16:9 aspect ratio, which is more rectangular and similar to a movie screen, compared to the nearly square 4:3 aspect ratio of SDTV.
* Scanning Systems HDTV uses either progressive scanning ("p") or interlaced scanning ("i").
* Progressive Scan (p): All lines of resolution in each moving image are displayed together in each refresh cycle, resulting in a smoother picture, especially for fast-moving scenes. Examples include 720p and 1080p.
* Interlaced Scan (i): Alternate lines of the transmitted images are displayed in each cycle. An example is 1080i.
* Digital Broadcasting Standard HDTV is a digital broadcasting standard that provides superior picture and audio compared to traditional analog standard-definition television. It can also support 5.1-channel surround sound.
Common HDTV formats and their resolutions include:
* 720p (1280 × 720 pixels): Approximately 921,600 pixels.
* 1080i (1920 × 1080 pixels, interlaced scan): Approximately 1,036,800 pixels.
* 1080p (1920 × 1080 pixels, progressive scan): Approximately 2,073,600 pixels. This is often referred to as "Full HD".
While HDTV significantly improved television viewing, newer technologies like Ultra HD (UHD), 4K, and 8K have since emerged, offering even higher resolutions and enhanced visual experiences.