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Hub AI
Deinterlacing AI simulator
(@Deinterlacing_simulator)
Hub AI
Deinterlacing AI simulator
(@Deinterlacing_simulator)
Deinterlacing
Deinterlacing is the process of converting interlaced video into a non-interlaced or progressive form. Interlaced video signals are commonly found in analog television, VHS, Betamax, Video 8, digital home video tapes such as Digital8 and DV tapes, CED Disc, Laserdisc, digital television (HDTV) when in the 1080i format, some DVD titles, and a smaller number of Blu-ray discs.
An interlaced video frame consists of two fields taken in sequence: the first containing all the odd lines of the image, and the second all the even lines. Analog television employed this technique because it allowed for less transmission bandwidth while keeping a high frame rate for smoother and more life-like motion. A non-interlaced (or progressive scan) signal that uses the same bandwidth only updates the display half as often and was found to create a perceived flicker or stutter. CRT-based displays were able to display interlaced video correctly due to their complete analog nature, blending in the alternating lines seamlessly. However, since the early 2000s, displays such as televisions and computer monitors have become almost entirely digital—in that the display is composed of discrete pixels—and on such displays the interlacing becomes noticeable and can appear as a distracting visual defect. The deinterlacing process should try to minimize these.
Deinterlacing is thus a necessary process and comes built-in to most modern DVD players, Blu-ray players, LCD/LED televisions, digital projectors, TV set-top boxes, professional broadcast equipment, and computer video players and editors—although each with varying levels of quality.
Deinterlacing has been researched for decades and employs complex processing algorithms; however, consistent results have been very hard to achieve.
Both video and photographic film capture a series of frames (still images) in rapid succession; however, television systems read the captured image by serially scanning the image sensor by lines (rows). In analog television, each frame is divided into two consecutive fields, one containing all even lines, another with the odd lines. The fields are captured in succession at a rate twice that of the nominal frame rate. For instance, PAL and SECAM systems have a rate of 25 frames/sec or 50 fields/sec, while the NTSC system delivers 29.97 frames/sec or 59.94 fields/sec. This process of dividing frames into half-resolution fields at double the frame rate is known as interlacing.
Since the interlaced signal contains the two fields of a video frame shot at two different times, it enhances motion perception to the viewer and reduces flicker by taking advantage of the persistence of vision effect. This results in an effective doubling of time resolution as compared with non-interlaced footage (for frame rates equal to field rates). However, interlaced signal requires a display that is natively capable of showing the individual fields in a sequential order, and only traditional CRT-based TV sets are capable of displaying interlaced signal, due to the electronic scanning and lack of apparent fixed resolution.
Most modern displays, such as LCD, DLP and plasma displays, are not able to work in interlaced mode, because they are fixed-resolution displays and only support progressive scanning. In order to display interlaced signal on such displays, the two interlaced fields must be converted to one progressive frame with a process known as de-interlacing. However, when the two fields taken at different points in time are re-combined to a full frame displayed at once, visual defects called interlace artifacts or combing occur with moving objects in the image. A good deinterlacing algorithm should try to avoid interlacing artifacts as much as possible and not sacrifice image quality in the process, which is hard to achieve consistently. There are several techniques available that extrapolate the missing picture information, however they rather fall into the category of intelligent frame creation and require complex algorithms and substantial processing power.
Deinterlacing techniques require complex processing and thus can introduce a delay into the video feed. While not generally noticeable, this can result in the display of older video games lagging behind controller input. Many TVs thus have a "game mode" in which minimal processing is done in order to maximize speed at the expense of image quality. Deinterlacing is only partly responsible for such lag; scaling also involves complex algorithms that take milliseconds to run.
Deinterlacing
Deinterlacing is the process of converting interlaced video into a non-interlaced or progressive form. Interlaced video signals are commonly found in analog television, VHS, Betamax, Video 8, digital home video tapes such as Digital8 and DV tapes, CED Disc, Laserdisc, digital television (HDTV) when in the 1080i format, some DVD titles, and a smaller number of Blu-ray discs.
An interlaced video frame consists of two fields taken in sequence: the first containing all the odd lines of the image, and the second all the even lines. Analog television employed this technique because it allowed for less transmission bandwidth while keeping a high frame rate for smoother and more life-like motion. A non-interlaced (or progressive scan) signal that uses the same bandwidth only updates the display half as often and was found to create a perceived flicker or stutter. CRT-based displays were able to display interlaced video correctly due to their complete analog nature, blending in the alternating lines seamlessly. However, since the early 2000s, displays such as televisions and computer monitors have become almost entirely digital—in that the display is composed of discrete pixels—and on such displays the interlacing becomes noticeable and can appear as a distracting visual defect. The deinterlacing process should try to minimize these.
Deinterlacing is thus a necessary process and comes built-in to most modern DVD players, Blu-ray players, LCD/LED televisions, digital projectors, TV set-top boxes, professional broadcast equipment, and computer video players and editors—although each with varying levels of quality.
Deinterlacing has been researched for decades and employs complex processing algorithms; however, consistent results have been very hard to achieve.
Both video and photographic film capture a series of frames (still images) in rapid succession; however, television systems read the captured image by serially scanning the image sensor by lines (rows). In analog television, each frame is divided into two consecutive fields, one containing all even lines, another with the odd lines. The fields are captured in succession at a rate twice that of the nominal frame rate. For instance, PAL and SECAM systems have a rate of 25 frames/sec or 50 fields/sec, while the NTSC system delivers 29.97 frames/sec or 59.94 fields/sec. This process of dividing frames into half-resolution fields at double the frame rate is known as interlacing.
Since the interlaced signal contains the two fields of a video frame shot at two different times, it enhances motion perception to the viewer and reduces flicker by taking advantage of the persistence of vision effect. This results in an effective doubling of time resolution as compared with non-interlaced footage (for frame rates equal to field rates). However, interlaced signal requires a display that is natively capable of showing the individual fields in a sequential order, and only traditional CRT-based TV sets are capable of displaying interlaced signal, due to the electronic scanning and lack of apparent fixed resolution.
Most modern displays, such as LCD, DLP and plasma displays, are not able to work in interlaced mode, because they are fixed-resolution displays and only support progressive scanning. In order to display interlaced signal on such displays, the two interlaced fields must be converted to one progressive frame with a process known as de-interlacing. However, when the two fields taken at different points in time are re-combined to a full frame displayed at once, visual defects called interlace artifacts or combing occur with moving objects in the image. A good deinterlacing algorithm should try to avoid interlacing artifacts as much as possible and not sacrifice image quality in the process, which is hard to achieve consistently. There are several techniques available that extrapolate the missing picture information, however they rather fall into the category of intelligent frame creation and require complex algorithms and substantial processing power.
Deinterlacing techniques require complex processing and thus can introduce a delay into the video feed. While not generally noticeable, this can result in the display of older video games lagging behind controller input. Many TVs thus have a "game mode" in which minimal processing is done in order to maximize speed at the expense of image quality. Deinterlacing is only partly responsible for such lag; scaling also involves complex algorithms that take milliseconds to run.