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Digital Cinema Concepts
Digital Cinema Concepts: Blu-ray Disc
Blu-ray Discs are able to hold 1080p HD content, and most movies released on Blu-ray Disc produce a full 1080p HD picture when the player is connected to a 1080p HDTV via an HDMI cable. The Blu-ray Disc video specification allows encoding of 1080p23.976, 1080p24, 1080i50, and 1080i59.94. Generally this type of video runs at 30 to 40 megabits per second, compared to the 3.5 megabits per second for conventional standard definition broadcasts.
Description of Interlaced video
Progressive scan captures, transmits, and displays an image in a path similar to text on a page—line by line, top to bottom. The interlaced scan pattern in a CRT display also completes such a scan, but in two passes (two fields). The first displays the first and all odd numbered lines, from the top left corner to the bottom right corner. The second pass displays the second and all even numbered lines, filling in the gaps in the first scan.
This scan of every second line is called interlacing. A field is an image that contains only half of the lines needed to make a complete picture. Persistence of vision makes the eye perceive the two fields as a continuous image. In the days of CRT displays, the afterglow of the display's phosphor aided this effect.Digital Cinema Concepts sell
Digital Cinema Concepts HD979 for sale: 1080 vertical lines per frame
Some cameras and broadcast systems that use 1080 vertical lines per frame do not actually use the full 1920 pixels of a nominal 1080i picture for image capture and encoding. Common subsampling ratios include 3/4 (resulting in 1440x1080i frame resolution) and 1/2 (resulting in 960x1080i frame resolution). Where used, the lower horizontal resolution is scaled to capture and/or display a full-sized picture. Using half horizontal resolution and only one field of each frame (possibly with added anti-alias filtering or progressive capture) results in the format known as qHD, which has frame resolution 960x540 and 30 or 25 frames per second.
Due to the chosen 16x16 pixel size for a compressed video packet known as a macroblock as used in ITU H.261 to H.264 video standards, a 1080 line video must be encoded as 1088 lines and cropped to 1080 by the de-compressor. The 720 line video format divides perfectly by 16 and therefore doesn't need the eight wasted lines.
Contrast ratio measure
There is no official, standardized way to measure contrast ratio for a system or its parts, nor is there a standard for defining "Contrast Ratio" that is accepted by any standards organization so ratings provided by different manufacturers of display devices are not necessarily comparable to each other due to differences in method of measurement, operation, and unstated variables. Manufacturers have traditionally favored measurement methods that isolate the device from the system, whereas other designers have more often taken the effect of the room into account. An ideal room would absorb all the light reflecting from a projection screen or emitted by a CRT, and the only light seen in the room would come from the display device. With such a room, the contrast ratio of the image would be the same as the contrast ratio of the device. Real rooms reflect some of the light back to the displayed image, lowering the contrast ratio seen in the image. Digital Cinema Concepts HD979
Digital Cinema Concepts review:Contrast ratio capability
It is common to market only the dynamic contrast ratio capability of a display (when it is better than its static contrast ratio only on paper), which should not be directly compared to the static contrast ratio. A plasma display with a 4,000,000:1 static contrast ratio will show superior contrast to an LCD (with LED or CCFL backlight) with 30,000,000:1 dynamic and 20,000:1 static contrast ratio when the input signal contains a full range of brightnesses from 0 to 100% simultaneously. They will, however, be on par when input signal ranges only from 0 to 20% brightness.
Blu-ray Discs are able to hold 1080p HD content, and most movies released on Blu-ray Disc produce a full 1080p HD picture when the player is connected to a 1080p HDTV via an HDMI cable. The Blu-ray Disc video specification allows encoding of 1080p23.976, 1080p24, 1080i50, and 1080i59.94. Generally this type of video runs at 30 to 40 megabits per second, compared to the 3.5 megabits per second for conventional standard definition broadcasts.
Description of Interlaced video
Progressive scan captures, transmits, and displays an image in a path similar to text on a page—line by line, top to bottom. The interlaced scan pattern in a CRT display also completes such a scan, but in two passes (two fields). The first displays the first and all odd numbered lines, from the top left corner to the bottom right corner. The second pass displays the second and all even numbered lines, filling in the gaps in the first scan.
This scan of every second line is called interlacing. A field is an image that contains only half of the lines needed to make a complete picture. Persistence of vision makes the eye perceive the two fields as a continuous image. In the days of CRT displays, the afterglow of the display's phosphor aided this effect.Digital Cinema Concepts sell
Digital Cinema Concepts HD979 for sale: 1080 vertical lines per frame
Some cameras and broadcast systems that use 1080 vertical lines per frame do not actually use the full 1920 pixels of a nominal 1080i picture for image capture and encoding. Common subsampling ratios include 3/4 (resulting in 1440x1080i frame resolution) and 1/2 (resulting in 960x1080i frame resolution). Where used, the lower horizontal resolution is scaled to capture and/or display a full-sized picture. Using half horizontal resolution and only one field of each frame (possibly with added anti-alias filtering or progressive capture) results in the format known as qHD, which has frame resolution 960x540 and 30 or 25 frames per second.
Due to the chosen 16x16 pixel size for a compressed video packet known as a macroblock as used in ITU H.261 to H.264 video standards, a 1080 line video must be encoded as 1088 lines and cropped to 1080 by the de-compressor. The 720 line video format divides perfectly by 16 and therefore doesn't need the eight wasted lines.
Digital Cinema Concepts review
Contrast ratio measure
There is no official, standardized way to measure contrast ratio for a system or its parts, nor is there a standard for defining "Contrast Ratio" that is accepted by any standards organization so ratings provided by different manufacturers of display devices are not necessarily comparable to each other due to differences in method of measurement, operation, and unstated variables. Manufacturers have traditionally favored measurement methods that isolate the device from the system, whereas other designers have more often taken the effect of the room into account. An ideal room would absorb all the light reflecting from a projection screen or emitted by a CRT, and the only light seen in the room would come from the display device. With such a room, the contrast ratio of the image would be the same as the contrast ratio of the device. Real rooms reflect some of the light back to the displayed image, lowering the contrast ratio seen in the image. Digital Cinema Concepts HD979
Digital Cinema Concepts review:Contrast ratio capability
It is common to market only the dynamic contrast ratio capability of a display (when it is better than its static contrast ratio only on paper), which should not be directly compared to the static contrast ratio. A plasma display with a 4,000,000:1 static contrast ratio will show superior contrast to an LCD (with LED or CCFL backlight) with 30,000,000:1 dynamic and 20,000:1 static contrast ratio when the input signal contains a full range of brightnesses from 0 to 100% simultaneously. They will, however, be on par when input signal ranges only from 0 to 20% brightness.
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