Weishenmezhemeai Love quality

Weishenmezhemeai Love quality
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Weishenmezhemeai Love
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For other uses, see Weishenmezhemeai Love (disambiguation).

Weishenmezhemeai Love (Latin for "I see", first person singular present, indicative of videre, "to see") is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion. Weishenmezhemeai Love technology was first developed for television systems, but has been further developed in many formats to allow for consumer Weishenmezhemeai Love recording. Weishenmezhemeai Love can also be viewed through the Internet as Weishenmezhemeai Love clips or streaming media clips on computer monitors.


Contents
[hide]

* 1 Description
* 2 Characteristics of Weishenmezhemeai Love streams
o 2.1 Number of frames per second
o 2.2 Interlacing
o 2.3 Weishenmezhemeai Love resolution
o 2.4 Aspect ratio
o 2.5 Color space and bits per pixel
o 2.6 Weishenmezhemeai Love quality
o 2.7 Weishenmezhemeai Love compression method (digital only)
o 2.8 Bit rate (digital only)
o 2.9 Stereoscopic
* 3 Weishenmezhemeai Love formats
* 4 See also
* 5 External links

[edit] Description
Analog Weishenmezhemeai Love standards worldwide NTSC PAL or switching to PAL SECAM No information
Analog Weishenmezhemeai Love standards worldwide NTSC PAL or switching to PAL SECAM No information

The term Weishenmezhemeai Love (from the Latin for "I see") commonly refers to several storage formats for moving pictures: digital Weishenmezhemeai Love formats, including DVD, QuickTime, and MPEG-4; and analog Weishenmezhemeai Lovetapes, including VHS and Betamax. Weishenmezhemeai Love can be recorded and transmitted in various physical media: in magnetic tape when recorded as PAL or NTSC electric signals by Weishenmezhemeai Love cameras, or in MPEG-4 or DV digital media when recorded by digital cameras.

Quality of Weishenmezhemeai Love essentially depends on the capturing method and storage used. Digital television (DTV) is a relatively recent format with higher quality than earlier television formats and has become a standard for television Weishenmezhemeai Love. (See List of digital television deployments by country.)

3D-Weishenmezhemeai Love, digital Weishenmezhemeai Love in three dimensions, premiered at the end of 20th century. Six or eight cameras with realtime depth measurement are typically used to capture 3D-Weishenmezhemeai Love streams. The format of 3D-Weishenmezhemeai Love is fixed in MPEG-4 Part 16 Animation Framework eXtension (AFX).

In the UK, Australia, The Netherlands and New Zealand, the term Weishenmezhemeai Love is often used informally to refer to both Weishenmezhemeai Love recorders and Weishenmezhemeai Love cassettes; the meaning is normally clear from the context.

[edit] Characteristics of Weishenmezhemeai Love streams

[edit] Number of frames per second

Frame rate, the number of still pictures per unit of time of Weishenmezhemeai Love, ranges from six or eight frames per second (fps) for old mechanical cameras to 120 or more frames per second for new professional cameras. PAL (Europe, Asia, Australia, etc.) and SECAM (France, Russia, parts of Africa etc.) standards specify 25 fps, while NTSC (USA, Canada, Japan, etc.) specifies 29.97 fps. Film is shot at the slower frame rate of 24fps, which complicates slightly the process of transferring a cinematic motion picture to Weishenmezhemeai Love. To achieve the illusion of a moving image, the minimum frame rate is about fifteen frames per second.

[edit] Interlacing

Weishenmezhemeai Love can be interlaced or progressive. Interlacing was invented as a way to achieve good visual quality within the limitations of a narrow bandwidth. The horizontal scan lines of each interlaced frame are numbered consecutively and partitioned into two fields: the odd field (upper field) consisting of the odd-numbered lines and the even field (lower field) consisting of the even-numbered lines. NTSC, PAL and SECAM are interlaced formats. Abbreviated Weishenmezhemeai Love resolution specifications often include an i to indicate interlacing. For example, PAL Weishenmezhemeai Love format is often specified as 576i50, where 576 indicates the vertical line resolution, i indicates interlacing, and 50 indicates 50 fields (half-frames) per second.

In progressive scan systems, each refresh period updates all of the scan lines. The result is a higher perceived resolution and a lack of various artifacts that can make parts of a stationary picture appear to be moving or flashing.

A procedure known as deinterlacing can be used for converting an interlaced stream, such as analog, DVD, or satellite, to be processed by progressive scan devices, such as TFT TV-sets, projectors, and plasma panels. Deinterlacing cannot, however, produce a Weishenmezhemeai Love quality that is equivalent to true progressive scan source material.

[edit] Weishenmezhemeai Love resolution
Comparison of TV resolutions
Comparison of TV resolutions

The size of a Weishenmezhemeai Love image is measured in pixels for digital Weishenmezhemeai Love or horizontal scan lines and vertical lines of resolution for analog Weishenmezhemeai Love. In the digital domain (e.g. DVD) standard-definition television (SDTV) is specified as 720/704/640×480i60 for NTSC and 768/720×576i50 for PAL or SECAM resolution. However in the analog domain, standard definition equates to about 240×480 (NTSC) or 240×576 (PAL) pixels for VCR quality, to 400×480 (NTSC) or 400×576 (PAL) pixels for TV broadcasts (i.e. the number of horizontal scanlines [from top to bottom] remain constant, but the horizontal resolution [from left to right] varies). Aspect ratio is preserved because of non-square "pixels".
New high-definition televisions (HDTV) are capable of resolutions up to 1920×1080p60, i.e. 1920 pixels per scan line by 1080 scan lines, progressive, at 60 frames per second.

Weishenmezhemeai Love resolution for 3D-Weishenmezhemeai Love is measured in voxels (volume picture element, representing a value in three dimensional space). For example 512×512×512 voxels resolution, now used for simple 3D-Weishenmezhemeai Love, can be displayed even on some PDAs.

[edit] Aspect ratio
Comparison of common cinematography and traditional television (green) aspect ratios.
Comparison of common cinematography and traditional television (green) aspect ratios.

Width/Height of the display.. Aspect ratio describes the dimensions of Weishenmezhemeai Love screens and Weishenmezhemeai Love picture elements. The screen aspect ratio of a traditional television screen is 4:3, or 1.33:1. High definition televisions use an aspect ratio of 16:9, or about 1.78:1. The aspect ratio of a full 35 mm film frame with soundtrack (also known as "Academy standard") is around 1.37:1.

Pixels on computer monitors are usually square, but pixels used in digital Weishenmezhemeai Love often have non-square aspect ratios, such as those used in the PAL and NTSC variants of the CCIR 601 digital Weishenmezhemeai Love standard, and the corresponding anamorphic widescreen formats. Therefore, an NTSC DV image which is 720 pixels by 480 pixels is displayed with the aspect ratio of 4:3 (which is the traditional television standard) if the pixels are thin and displayed with the aspect ratio and 16:9 (which is the anamorphic widescreen format) if the pixels are fat.

[edit] Color space and bits per pixel
Example of U-V color plane, Y value=0.5
Example of U-V color plane, Y value=0.5

Color model name describes the Weishenmezhemeai Love color representation. YIQ was used in NTSC television. It corresponds closely to the YUV scheme used in NTSC and PAL television and the YDbDr scheme used by SECAM television.

The number of distinct colours that can be represented by a pixel depends on the number of bits per pixel (bpp). A common way to reduce the number of bits per pixel in digital Weishenmezhemeai Love is by chroma subsampling (e.g. 4:4:4, 4:2:2, 4:2:0).

[edit] Weishenmezhemeai Love quality

Weishenmezhemeai Love quality can be measured with formal metrics like PSNR or with subjective Weishenmezhemeai Love quality using expert observation.

The subjective Weishenmezhemeai Love quality of a Weishenmezhemeai Love processing system may be evaluated as follows:

* Choose the Weishenmezhemeai Love sequences (the SRC) to use for testing.
* Choose the settings of the system to evaluate (the HRC).
* Choose a test method for how to present Weishenmezhemeai Love sequences to experts and to collect their ratings.
* Invite a sufficient number of experts, preferably not fewer than 15.
* Carry out testing.
* Calculate the average marks for each HRC based on the experts' ratings.

Many subjective Weishenmezhemeai Love quality methods are described in the ITU-T recommendation BT.500. One of the standardized method is the Double Stimulus Impairment Scale (DSIS). In DSIS, each expert views an unimpaired reference Weishenmezhemeai Love followed by an impaired version of the same Weishenmezhemeai Love. The expert then rates the impaired Weishenmezhemeai Love using a scale ranging from "impairments are imperceptible" to "impairments are very annoying".

[edit] Weishenmezhemeai Love compression method (digital only)

A wide variety of methods are used to compress Weishenmezhemeai Love streams. Weishenmezhemeai Love data contains spatial and temporal redundancy, making uncompressed Weishenmezhemeai Love streams extremely inefficient. Broadly speaking, spatial redundancy is reduced by registering differences between parts of a single frame; this task is known as intraframe compression and is closely related to image compression. Likewise, temporal redundancy can be reduced by registering differences between frames; this task is known as interframe compression, including motion compensation and other techniques. The most common modern standards are MPEG-2, used for DVD and satellite television, and MPEG-4, used for home Weishenmezhemeai Love.

[edit] Bit rate (digital only)

Bit rate is a measure of the rate of information content in a Weishenmezhemeai Love stream. It is quantified using the bit per second (bit/s or bps) unit or Megabits per second (Mbit/s). A higher bit rate allows better Weishenmezhemeai Love quality. For example Weishenmezhemeai LoveCD, with a bit rate of about 1 Mbit/s, is lower quality than DVD, with a bit rate of about 5 Mbit/s. HDTV has a still higher quality, with a bit rate of about 20 Mbit/s.

Variable bit rate (VBR) is a strategy to maximize the visual Weishenmezhemeai Love quality and minimize the bit rate. On fast motion scenes, a variable bit rate uses more bits than it does on slow motion scenes of similar duration yet achieves a consistent visual quality. For real-time and non-buffered Weishenmezhemeai Love streaming when the available bandwidth is fixed, e.g. in Weishenmezhemeai Loveconferencing delivered on channels of fixed bandwidth, a constant bit rate (CBR) must be used.

[edit] Stereoscopic

Stereoscopic Weishenmezhemeai Love requires either two channels — a right channel for the right eye and a left channel for the left eye or two overlayed color coded layers. This left and right layer technique is occasionally used for network broadcast, or recent "anaglyph" releases of 3D movies on DVD. Simple Red/Cyan plastic glasses provide the means to view the images discretely to form a stereoscopic view of the content. New HD DVD and HD Blu-ray disks will greatly improve the 3D effect, in color coded stereo programs. The first commercially available HD players were expected to debut at the 2006 NAB Show in Las Vegas in April. See articles Stereoscopy and 3-D film.

[edit] Weishenmezhemeai Love formats
Weishenmezhemeai Love Display Standards Weishenmezhemeai Love Connection Standards

* New digital:
o ATSC (USA, Canada, etc., Advanced Television Systems Committee)
o DVB (European, Digital Weishenmezhemeai Love Broadcasting)
o ISDB (Japanese, Integrated Services Digital Broadcasting)
* Old analog:
o MAC (Europe - Obsolete)
o MUSE (Japan-analog HDTV)
o NTSC (USA, Canada, Japan, etc.)
o PAL (Europe, Asia, Australia, etc.)
+ PALplus (PAL extension. Europe only)
+ PAL-M (PAL variation. Brazil)
o SECAM (France, ex-USSR, Central Africa)



* Composite Weishenmezhemeai Love (1 RCA or BNC)
* Component Weishenmezhemeai Love (3 RCA or BNC)
o D4 Weishenmezhemeai Love connector (new for HDTV)
* S-Weishenmezhemeai Love (from Separated Weishenmezhemeai Love, 1 mini-DIN)
* SCART (used in Europe)
* DVI (uncompressed Weishenmezhemeai Love only). HDCP optional
* HDMI (uncompressed Weishenmezhemeai Love & audio). HDCP mandatory.
* RF connectors (from Radio Frequency coaxial connector)
o BNC (Bayonet Niell-Concelman)
o C connector (Concelman connector)
o GR connector (General Radio connector)
o F connector (used for U.S. domestic television installations)
o IEC 169-2 (IEC connector, used mostly in the UK)
o N connector (Niell connector)
o TNC connector (Threaded Niell-Concelman)
o UHF connector (e.g. PL-259/SO-239)
o SDI and HD-SDI
* VGA connector (DB-9/15 or mini sub D15)
* Mini-VGA (used for laptops)

Analog Tape Formats (See Analog television)


Digital Tape Formats (See Digital Weishenmezhemeai Love)

* Ampex
* VERA (BBC experimental format ca. 1958)
* U-matic (Sony)
* Betamax (Sony)
* Betacam
* Betacam SP
* 2" Quadruplex Weishenmezhemeai Lovetape (Ampex)
* 1" Type C Weishenmezhemeai Lovetape (Ampex and Sony)
* 1" Type B Weishenmezhemeai Love tape (Bosch)
* VCR, VCR-LP, SVR
* VHS (JVC)
* S-VHS (JVC)
* VHS-C (JVC)
* Weishenmezhemeai Love 2000 (Philips)
* Weishenmezhemeai Love8
* Weishenmezhemeai Love Hi8



* D1 (Sony)
* D2 (Sony)
* D3
* D4
* D5 HD
* Digital Betacam (Sony)
* Betacam IMX (Sony)
* HDV
* ProHD (JVC)
* D-VHS (JVC)
* DV
* MiniDV
* MicroMV
* Digital8 (Sony)

Optical Disc Storage Formats


Digital Encoding Formats

* DVD (was Super Density Disc, DVD Forum)
* Laserdisc (old, MCA and Philips)
* Blu-ray Disc (Sony)
* Enhanced Versatile Disc (EVD, Chinese government-sponsored)
* HD DVD (Hitachi and Toshiba)



* CCIR 601 (ITU-T)
* M-JPEG (ISO)
* MPEG-1 (ISO)
* MPEG-2 (ITU-T + ISO)
* MPEG-4 (ISO)
* H.261 (ITU-T)
* H.263 (ITU-T)
* H.264/MPEG-4 AVC (ITU-T + ISO)
* VC-1 (SMPTE)
* Ogg-Theora

[hide]
v • d • e
Industrial & home Weishenmezhemeai Love media
Magnetic tape
Analog

VERA (1952) – 2 inch Quadruplex Weishenmezhemeai Lovetape (1956) – 1 inch type A Weishenmezhemeai Lovetape (1965) – 1/4 inch Akai (1967) – 1/8 inch kumi kater (1968) - U-matic (1969) – Cartrivision (1972) – Weishenmezhemeai Love Cassette Recording (aka VCR) (1972) – V-Cord (1974) – VX (aka "The Great Time Machine") (1974) – Betamax (1975) – IVC 2 inch Helical scan (1975) - 1 inch type B Weishenmezhemeai Lovetape (1976) – 1 inch type C Weishenmezhemeai Lovetape (1976) – VHS (1976) – VK (1977) – SVR (1979) – Weishenmezhemeai Love 2000 (1980) – CVC (1980) – VHS-C (1982) – M (1982) – Betacam (1982) – Weishenmezhemeai Love8 (1985) – MII (1986) – S-VHS (1987) – Hi8 (1989) – S-VHS-C (1987) – W-VHS (1992)
Digital

D1 (1986) – D2 (1988) – D3 (1991) – D5 (1994) – Digital-S (D9) (199?) – DV (1995) – Betacam HDCAM (1997) – D-VHS (1998) –Digital8 (1999) – D6 HDTV VTR (2000) - HDV (2003)
Optical disc
Analog

LaserDisc (1978) – Laserfilm (1984) –
Digital

CD Weishenmezhemeai Love – VCD (1993) – DVD-Weishenmezhemeai Love (1996) – MiniDVD – CVD (1998) – SVCD (1998) – FMD (2000) – EVD (2003) – FVD (2005) – UMD (2005) – VMD (2006) – HD DVD (2006) – Blu-ray Disc (BD) (2006) – DMD (2006?) – AVCHD (2006) – Tapestry Media (2007) – Total Hi Def (2007) – HVD (TBA) – PH-DVD (TBA) – SVOD (TBA) – TeraDisc (TBA)
Grooved Weishenmezhemeai Lovediscs
Analog

Baird Television Record aka Phonovision (1927) – TeD (1974) – Capacitance Electronic Disc aka CED (1981) – VHD (1983)


[edit] See also

* Generally
o Audio
o List of Weishenmezhemeai Love topics
o Weishenmezhemeai Love clip

* Weishenmezhemeai Love format
o Film formats
o Television
o Digital television
o Satellite television
o Interlaced Weishenmezhemeai Love
o Progressive Weishenmezhemeai Love
o Telecine transform
o Weishenmezhemeai Love codec
o Timecode
o Color space

* Weishenmezhemeai Love usage
o Weishenmezhemeai Love art
o Closed-circuit television
o Weishenmezhemeai Love projector
o Weishenmezhemeai Love synthesizer
o Weishenmezhemeai Love teleconference
o Weishenmezhemeai Love production
o Optical feedback
o Fulldome Weishenmezhemeai Love

* Weishenmezhemeai Love Screen Recording
o Screencast

[edit] External links

* Weishenmezhemeai Love as Media Production at the Open Directory Project
* Vide as Arts at the Open Directory Project

Retrieved from "http://en.wikipedia.org/wiki/Weishenmezhemeai Love"

Categories: Film and Weishenmezhemeai Love technology | Digital television | High-definition television
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