Advantages of Progressive Scan

Generally speaking, progressive scanning has its own advantages when compared with interlaced scanning. First of all, the main advantage with progressive scanning is that the motion will be smoother and more realistic. In contrast, the interlaced video of the same rate will have a lot of visual artifacts, such as interline twitter. When capturing video with progressive scan, people have no such worries. It is safe to say that there will be an absence of visual artifacts, which enables the captured image to be used as still photos.

As a result, there is no need in intentional blurring, namely, anti-aliasing, of video in order to reduce interline twitter and eye strain. As a matter of fact, in the case of most media such as DVD movies and video games, the video is automatically blurred during the authoring process itself to subdue interline twitter when played back on interlace displays. Therefore, it is entirely impossible to recover the sharpness of the original video if the vide has been viewed progressively. A feasible solution to this problem is that people are supposed to choose the display hardware and video games come equipped with options to blur the video at will or to keep it at its original sharpness. Under such circumstance, the viewer is able to achieve the desired image sharpness no matter whether he is adopting interlaced or progressive displays.

Actually, progressive video is clearer and faster for scaling to higher resolutions in comparison with its equivalent interlaced video. HDTVs not based on CRT technology cannot natively display interlaced video. Therefore, the interlaced video has to be deinterlaced before it is scaled and displayed on HDTVs. However, in the deinterlacing process, some noticeable artifacts and input lag between the video source and display device are likely to emerge.

About Progressive Scan

Progressive scanning refers to a way of displaying, storing or transmitting moving images in which all the lines of each frame are drawn in sequence. It is also known as noninterlaced scanning alternatively. In comparison with interlaced video, progressive scanning is a way distinguished from interlaced scanning. Interlaced video is usually adopted in traditional analog television systems in which only the odd lines, then the even lines of each frame (each image called a video field) are drawn one after another. As a result, only half of the number of actual image frames are utilized to produce video.

As a matter of fact, progressive scanning is known as “sequential scanning” in the first place when it was adopted in the Baird 240 line television transmissions from Alexandra Palace, United Kingdom in 1936. Nowadays, progressive scanning has been universally adopted in computing.

Progressive scanning is applied in the scanning and storing of film-based material on DVDs. It was agreed that all film transmissions by HDTV would be broadcast with progressive scan in the US. Even though the video signal is sent interlaced, an HDTV will convert it to progressive scan.

Progressive scanning has been applied on most Cathode ray tube (CRT) computer monitors, all LCD computer monitors, and most HDTVs for the display resolutions are progressive by nature. Other CRT-type displays, such as SDTVs, will only display interlaced video.

Generally speaking, some TVs and most video projectors have one or more progressive scan inputs. Before HDTV became well received, some high end displays supported 480p. Under such conditions, these displays were able to be used with devices outputting progressive scan. For instance, some progressive scan DVD players and certain video game consoles are included. HDTVs support the 480p and 720p resolutions which have been progressively scanned. Compared with lower resolution HDTV models, the 1080p displays are usually more expensive.