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Digital Cinema Concepts
Digital Cinema Concepts HD979: Interlaced video broadcasting
The European Broadcasting Union has argued against interlaced video in production and broadcasting. They recommend 720p 50 fps (frames per second) for the current production format—and are working with the industry to introduce 1080p50 as a future-proof production standard. 1080p 50 offers higher vertical resolution, better quality at lower bitrates, and easier conversion to other formats, such as 720p50 and 1080i50. The main argument is that no matter how complex the deinterlacing algorithm may be, the artifacts in the interlaced signal cannot be completely eliminated because some information is lost between frames.
Despite arguments against it, television standards organizations continue to support interlacing. It is still included in digital video transmission formats such as DV, DVB, and ATSC. New video compression standards in development, like High Efficiency Video Coding, do not support interlaced coding tools and target high-definition progressive video such as ultra high definition television.
Broadcast standard 1080i
Within the designation "1080i", the i stands for interlaced scan. A frame of 1080i video consists of two sequential fields of 1920 horizontal and 1080 vertical pixels. The first field consists of all odd-numbered TV lines and the second all even numbered lines. Consequently the horizontal lines of pixels in each field are captured and displayed with a one-line vertical gap between them, so the lines of the next field can be interlaced between them, resulting in 1080 total lines. 1080i differs from 1080p, where the p stands for progressive scan, where all lines in a frame are captured at the same time. In native or pure 1080i, the two fields of a frame correspond to different instants (points in time), so motion portrayal is good (50 or 60 motion phases/second). This is true for interlaced video in general and can be easily observed in still images taken from fast motion scenes, as shown in the figure on the right (without appropriate deinterlacing). However when 1080p material is captured at 25 or 30 frames/second it is converted to 1080i at 50 or 60 fields/second, respectively, for processing or broadcasting. In this situation both fields in a frame do correspond to the same instant. The field-to-instant relation is somewhat more complex for the case of 1080p at 24 frames/second converted to 1080i at 60 fields/second.Digital Cinema Concepts
Digital Cinema Concepts HD979 for sale: Interlaced scan
Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all odd lines in the image, the other contains all even lines.
A PAL-based television set display, for example, scans 50 fields every second (25 odd and 25 even). The two sets of 25 fields work together to create a full frame every 1/25 of a second (or 25 frames per second), but with interlacing create a new half frame every 1/50 of a second (or 50 fields per second). To display interlaced video on progressive scan displays, playback applies deinterlacing to the video signal (which adds input lag).
Dynamic contrast:
A notable recent development in LCD technology is "dynamic contrast" (DC), also called "advanced contrast ratio" (ACR) and various other designations. When there is a need to display a dark image, a display that supports dynamic contrast underpowers the backlight lamp (or decreases the aperture of the projector's lens using an iris), but proportionately amplifies the transmission through the LCD panel; this gives the benefit of realizing the potential static contrast ratio of the LCD panel in dark scenes when the image is watched in a dark room. The drawback is that if a dark scene contains small areas of superbright light, the resulting image may be over exposed. Digital Cinema Concepts sell
Digital Cinema Concepts review:Dynamic contrast - Brightness
The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions.
Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen.
The European Broadcasting Union has argued against interlaced video in production and broadcasting. They recommend 720p 50 fps (frames per second) for the current production format—and are working with the industry to introduce 1080p50 as a future-proof production standard. 1080p 50 offers higher vertical resolution, better quality at lower bitrates, and easier conversion to other formats, such as 720p50 and 1080i50. The main argument is that no matter how complex the deinterlacing algorithm may be, the artifacts in the interlaced signal cannot be completely eliminated because some information is lost between frames.
Despite arguments against it, television standards organizations continue to support interlacing. It is still included in digital video transmission formats such as DV, DVB, and ATSC. New video compression standards in development, like High Efficiency Video Coding, do not support interlaced coding tools and target high-definition progressive video such as ultra high definition television.
Broadcast standard 1080i
Within the designation "1080i", the i stands for interlaced scan. A frame of 1080i video consists of two sequential fields of 1920 horizontal and 1080 vertical pixels. The first field consists of all odd-numbered TV lines and the second all even numbered lines. Consequently the horizontal lines of pixels in each field are captured and displayed with a one-line vertical gap between them, so the lines of the next field can be interlaced between them, resulting in 1080 total lines. 1080i differs from 1080p, where the p stands for progressive scan, where all lines in a frame are captured at the same time. In native or pure 1080i, the two fields of a frame correspond to different instants (points in time), so motion portrayal is good (50 or 60 motion phases/second). This is true for interlaced video in general and can be easily observed in still images taken from fast motion scenes, as shown in the figure on the right (without appropriate deinterlacing). However when 1080p material is captured at 25 or 30 frames/second it is converted to 1080i at 50 or 60 fields/second, respectively, for processing or broadcasting. In this situation both fields in a frame do correspond to the same instant. The field-to-instant relation is somewhat more complex for the case of 1080p at 24 frames/second converted to 1080i at 60 fields/second.Digital Cinema Concepts
Digital Cinema Concepts HD979 for sale: Interlaced scan
Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all odd lines in the image, the other contains all even lines.
A PAL-based television set display, for example, scans 50 fields every second (25 odd and 25 even). The two sets of 25 fields work together to create a full frame every 1/25 of a second (or 25 frames per second), but with interlacing create a new half frame every 1/50 of a second (or 50 fields per second). To display interlaced video on progressive scan displays, playback applies deinterlacing to the video signal (which adds input lag).
Digital Cinema Concepts review
Dynamic contrast:
A notable recent development in LCD technology is "dynamic contrast" (DC), also called "advanced contrast ratio" (ACR) and various other designations. When there is a need to display a dark image, a display that supports dynamic contrast underpowers the backlight lamp (or decreases the aperture of the projector's lens using an iris), but proportionately amplifies the transmission through the LCD panel; this gives the benefit of realizing the potential static contrast ratio of the LCD panel in dark scenes when the image is watched in a dark room. The drawback is that if a dark scene contains small areas of superbright light, the resulting image may be over exposed. Digital Cinema Concepts sell
Digital Cinema Concepts review:Dynamic contrast - Brightness
The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions.
Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen.
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