HD TV was first introduced almost a decade ago and has changed the way we view and enjoy our media content. One of the key factors that make HDTVs so successful is their image scanning technology (method of displaying content). There are two main scanning methods, interlaced scanning and progressive scanning. Interlaced scanning has deeper roots than progressive scanning which was first introduced in LCD Monitors and DVD players.
Because progressive scanning produces more impressive images than interlaced in some instances, it is used for recorded content as well as some broadcasting standards. Interlaced scanning was first used for analogue and has a history with the first generations of High-Definition TVs (now standard definition TVs), although there has been some debate about which is more suitable for broadcasting, interlaced scanning has been adopted by most broadcasters. There are a few broadcasters that still use progressive scanning although only in the 720p format not full HD 1080p (which is superior by most standards to 1080i, the broadcasting format used by broadcasters.) Also progressive scanning is the standard used for digital media content, DVD/Blu-ray discs (where it has been very successful) and streaming platforms.
Here is a comparison of progressive and interlaced scanning:
Progressive scanning produces much better results for scaling to higher resolutions than equivalent interlaced scanning does for video, such as up scaling or up converting 480p to display on a 1080p HDTV. Also progressive scaling works better with full video frames which are common on streamed, digital and optical media whereas interlaced video must be unlocked as it were or “deinterlaced” before it is scaled, which can result in a poor picture resolution.
Interlaced scanning is better for broadcasting than media content. Progressive scanning relies on data bits or small pieces of content that are built and displayed progressively whereas interlaced scanning builds the images/content in odd and even lines which can create flickering. For broadcasting purposes, interlaced scanning is better as it requires less bandwidth than progressive scanned at the same frame size and vertical refresh which would explain why most broadcasters use 720p or 1080i instead of full HD 1080p.
As an image scanning technology, progressive scanning is ideal for certain applications of HD but not all. Is it the future of HDTV? This remains to be seen but it is a very serious contender to be employed full scale. For the average consumer, progressive scanning benefits will be seen mostly in digital content while interlaced scanning will be common in HD broadcasting. It is best to get an HDTV that supports both scanning technologies to future-proof any HD experience.
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