A weighting filter is used to emphasise or suppress some aspects of a phenomenon compared to others, for measurement or other purposes. Weighting filter - Audio applications. In each field of audio measurement, special units are used to indicate a weighted measurement as opposed to a basic physical measurement of energy level. For sound, the unit is the phon (1 kHz equivalent level). Weighting filter - Loudness measurements. In the measurement of loudness, for exam ...

Including:

• Weighting filter - Audio applications
• Weighting filter - Loudness measurements
• Weighting filter - Telecommunications
• Weighting filter - Environmental noise measurement
• Weighting filter - Audio reproduction and broadcasting equipment
• Weighting filter - Other applications of weighting

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The contrast ratio is a metric of a video display, defined as the ratio of the light intensity of the brightest possible color to the darkest possible color a display is capable of displaying simultaneously. The higher the contrast ratio, the better the display is. Examples are 800:1, 700:1, and 500:1 from higher to lower capability. Infinite contrast ratios can be achieved by devices capable of emitting no light at all as their darkest color. Contrast ratio is most commonly considered in connection with transmissive dis ...

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Binocular rivalry is a phenomenon of visual perception in which perception alternates between different images presented to each eye. When one image is presented to one eye and a very different image is presented to the other, instead of the two images being seen superimposed, one image is seen for a few moments, then the other, then the first, and so on, randomly for as long as one cares to look. For example if a set of vertical lines is presented to one eye, and a set of horizontal lines to the same region of the retina of the other ...

Including:

• Binocular rivalry - Types of binocular rivalry
• Binocular rivalry - Why binocular rivalry is interesting
• Binocular rivalry - History of binocular rivalry
• Binocular rivalry - Early theories of binocular rivalry
• Binocular rivalry - Empirical studies of binocular rivalry: B. B. Breese 1899 1909

Read more here: » Binocular rivalry: Encyclopedia - Binocular rivalry

Brightness is an attribute of visual perception in which a source appears to emit a given amount of light. In other words, brightness is the perception elicited by the luminance of a visual target. "Brightness" was formerly used as a synonym for the photometric term luminance and (incorrectly) for the radiometric term radiance. According to Federal Standard 1037C, "brightness" should now be used only for nonquantitative references to physiological sensations and perceptions of light. Note, that the same target luminance can elicit different perceptions of brightness in different contexts. (See, e.g. ...

Including:

• Brightness - Helping links

Read more here: » Brightness: Encyclopedia - Brightness

YIQ is a color space formerly used in the NTSC television standard. I stands for in-phase, while Q stands for quadrature. NTSC now uses the YUV color space, which is also used by other systems such as PAL. The Y component represents the luminance information, and is the only component used by black-and-white television receivers. I and Q represent the chrominance information. In YUV, the U and V components can be thought of as X and Y coordinates within the colorspace. I and Q can be thought of as a second pair of axes on the same graph, rotated 33°; therefore IQ and UV represent diffe ...

Including:

• YIQ - Formula

Read more here: » YIQ: Encyclopedia - YIQ

A charge-coupled device (CCD) is a sensor for recording images, consisting of an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to one or other of its neighbours. CCDs are used in digital photography and astronomy (particularly in photometry, optical and UV spectroscopy and high speed techniques such as lucky imaging). Charge-coupled device - History. The CCD was invented ...

Including:

• Charge-coupled device - History
• Charge-coupled device - Applications
• Charge-coupled device - Color cameras
• Charge-coupled device - Competing technologies

Read more here: » Charge-coupled device: Encyclopedia - Charge-coupled device

The YUV model defines a color space in terms of one luminance and two chrominance components. YUV is used in the PAL and NTSC systems of television broadcasting, which is the standard in much of the world. YUV models human perception of color more closely than the standard RGB model used in computer graphics hardware, but not as closely as the HSV color space. Y stands for the luminance component (the brightness) and U and V are the chrominance (color) components. The YCbCr or YPbPr color space, used in component video, ...

Including:

• YUV - Luminance/chrominance systems in general
• YUV - Types of sampling

Read more here: » YUV: Encyclopedia - YUV

The Video Home System, first released in September 1976, better known by its abbreviation VHS, is a recording and playing standard for video cassette recorders (VCRs), developed by JVC (with some of its critical technology under lucrative licensing agreements with Sony) and launched in 1976. VHS officially stands for Video Home System, but it initially stood for Vertical Helical Scan, after the relative head/tape scan technique. Some early reports claim the name origin ...

Including:

• VHS - Technical details
• VHS - Variations
• VHS - Signal Standards
• VHS - Tape Lengths
• VHS - VHS vs. Betamax
• VHS - DVD and the decline of VHS
• VHS - List of notable VHS companies

Read more here: » VHS: Encyclopedia - VHS

Y is the twenty-fifth letter of the Latin alphabet. Its name in English is wy, sometimes spelled wye. See V. In Ancient Greek Υψιλον (Ypsilon) was pronounced IPA [u], later on [y], now [i]. The Romans borrowed Y directly from the Greek, because they felt that V no longer adequately represented Greek [y]. The letter Y was used in Old English, as in Latin, with the value [y]; however, some think that this use was an independent invention in England created by stacking a V and an I, unrelated to the Lati ...

Including:

• Y - Codes for computing
• Y - Meanings of Y

Read more here: » Y: Encyclopedia - Y

CCDs containing grids of pixels are used in digital cameras, optical scanners and video cameras as light-sensing devices. They commonly respond to 70% of the incident light (meaning a quantum efficiency of about 70%) making them more efficient than photographic film, which captures only about 2% of the incident light. As a result CCDs were rapidly adopted by astronomers. An image is projected by a lens on the capacitor array, causing each capacitor to accumulate an electric charge proportional to the light intensity at that location. ...

See also:

Charge-coupled device, Charge-coupled device - History, Charge-coupled device - Applications, Charge-coupled device - Color cameras, Charge-coupled device - Competing technologies

Read more here: » Charge-coupled device: Encyclopedia II - Charge-coupled device - Applications

The opponent colour theory was first proposed by Ewald Hering in 1872 (Hering, 1964). He thought that the colours red, yellow, green, and blue are special in that any other colour can be described as a mix of them, and that they exist in opposite pairs. That is, either red or green is perceived and never greenish-red. (Note that although yellow is a mixture of red and green in the RGB color theory, the eye does not perceive it as such.) In 1957 Leo Hurvich and Dorothea Jameson provided quantitative data for Hering's col ...

See also:

Opponent process, Opponent process - History, Opponent process - Reddish green and yellowish blue

Read more here: » Opponent process: Encyclopedia II - Opponent process - History

Commodore 64 peripherals - Floppy disk drives. Although not always supplied with the machine, floppy disk drives of the 5¼ inch (Commodore 1541 and 1571) and, later, 3½ inch (1581) variety were available. The 1541 was excruciatingly slow in loading programs because of a poorly-implemented serial bus, a legacy of the Commodore VIC-20. A common joke advised users to "go grab a cup of hot chocolate milk" afte ...

See also:

Commodore 64 peripherals, Commodore 64 peripherals - Storage, Commodore 64 peripherals - Floppy disk drives, Commodore 64 peripherals - Tape drives, Commodore 64 peripherals - Hard Drives and expansions, Commodore 64 peripherals - Input/Output, Commodore 64 peripherals - Serial communications, Commodore 64 peripherals - RAM expansions, Commodore 64 peripherals - Input devices, Commodore 64 peripherals - Other peripherals, Commodore 64 peripherals - Notes

Read more here: » Commodore 64 peripherals: Encyclopedia II - Commodore 64 peripherals - Storage

Just as the other color standards adopted for broadcast usage over the world, SÉCAM is a compatible standard, which means that Monochrome television receivers predating its introduction are still able to show the programs, although only in black and white. Because of this compatibility requirement, color standards add a second signal to the basic monochrome signal, and this signal carries the color information, called chrominance or C in short, while the black and white information is called the luminance (Y in short). Old TV receivers only see the luminance, ...

See also:

SÉCAM, SÉCAM - Technical details, SÉCAM - History, SÉCAM - Why SÉCAM in France?, SÉCAM - Why SÉCAM elsewhere?, SÉCAM - SÉCAM varieties, SÉCAM - Problems with the standard, SÉCAM - Facetious interpretations of the SÉCAM acronym, SÉCAM - Countries and territories that use or have used SÉCAM

Read more here: » SÉCAM: Encyclopedia II - SÉCAM - Technical details

All analogue television systems began life in monochrome. Each country, faced with local political, technical, and economic issues, adopted a color system which was effectively grafted on to an existing monochrome system, using gaps in the video spectrum (explained below) to allow the color information to fit in the channels allotted. In theory, any color system could be used with any monochrome video system, but in practice some of the original monochrome systems proved impractical to adapt to color and were abandoned when the switch to color broadcasting wa ...

See also:

Broadcast television system, Broadcast television system - Analogue television systems, Broadcast television system - Frames, Broadcast television system - Viewing technology, Broadcast television system - Hidden signalling, Broadcast television system - Interlacing, Broadcast television system - Image polarity, Broadcast television system - Modulation, Broadcast television system - Audio, Broadcast television system - Evolution, Broadcast television system - ITU identification scheme, Broadcast television system - Table of world TV systems, Broadcast television system - Digital television systems, Broadcast television system - Digital television systems modulation, Broadcast television system - ATSC, Broadcast television system - DVB-T

Read more here: » Broadcast television system: Encyclopedia II - Broadcast television system - Analogue television systems

A VHS cassette contains a ½ inch (12.7 mm) wide magnetic tape wound between two spools, allowing it to be slowly passed over the various playback and recording heads of the video cassette recorder. The tape speed is 3.335 cm/s for NTSC, 2.339 cm/s for PAL. A cassette holds a maximum of about 430 m of tape at the lowest acceptable tape thickness, giving a maximum playing time of about 3.5 hours for NTSC and 5 hours for PAL at "standard" (SP) quality. Most cassettes have lower recording times because they use thicker tape, which helps avoid j ...

See also:

VHS, VHS - Technical details, VHS - Variations, VHS - Signal Standards, VHS - Tape Lengths, VHS - VHS vs. Betamax, VHS - DVD and the decline of VHS, VHS - List of notable VHS companies

Read more here: » VHS: Encyclopedia II - VHS - Technical details

The purpose of saccades can be illustrated by the human eye. Humans do not look at a scene in a steady way. Instead, the eyes move around, locating interesting parts of the scene and building up a mental 'map' corresponding to the scene. In the human eye, one reason for saccades is that only the central part of the retina, the macula, has a high concentration of color sensitive nerve cells, called cone cells. The rest of the retina is mainly made up of monochrome nerve endings called rod cells, which are especially good for motion detection. Thus, the macula makes up the hi ...

See also:

Saccade, Saccade - Saccadic eye motion, Saccade - Saccadic masking, Saccade - Comparative physiology

Read more here: » Saccade: Encyclopedia II - Saccade - Saccadic eye motion

Information stored in high dynamic range (HDR) images usually correspond to the physical values of luminance or radiance that can be observed in the real world. This is different to traditional digital images, which represent colors that should appear on a monitor or a paper print. Therefore HDR image formats are often called scene-referred, in contrast to traditional digital images, which are device-referred or output-referred. Furthermore, traditional images are usually encoded for the human visual system (maximizing the visual information ...

See also:

High dynamic range imaging, High dynamic range imaging - Difference between high dynamic range and traditional digital images

Read more here: » High dynamic range imaging: Encyclopedia II - High dynamic range imaging - Difference between high dynamic range and traditional digital images

Like VHS, the S-VHS format uses a "color under" modulation scheme. S-VHS improves VHS's luminance resolution by boosting the frequency deviation of the luminance carrier. This produces a 60% improvement in (luminance) picture detail, or a horizontal resolution of 400 "picture elements" (versus VHS's horizontal resolution of 240 picture elements.) The often quoted horizontal resolution of 400 means S-VHS captures greater picture detail than even analog (NTSC) cable broadcast TV. In practice, when timeshifting TV programs on S-VHS equipment, t ...

See also:

S-VHS, S-VHS - Technical details, S-VHS - Shadow of VHS, S-VHS - S-VHS vs ED-Beta, S-VHS - Home Use

Read more here: » S-VHS: Encyclopedia II - S-VHS - Technical details

There is also a HDTV version of SDI called High Definition Serial Digital Interface (HD-SDI). It is specified in SMPTE-292M. This standard transmits audio and video over a single coaxial cable with a datarate of 1.485 Gbit/s. Link. The SMPTE-292 specifications is a serialized version of a parallel digital video stream along with embedded data that can pertain to time code, audio, or other features. Th ...

See also:

Serial Digital Interface, Serial Digital Interface - HD-SDI, Serial Digital Interface - Technical details of the data format

Read more here: » Serial Digital Interface: Encyclopedia II - Serial Digital Interface - HD-SDI

Radiance is defined by where the approximation holds for small A and Ω, L is the radiance (W·m-2·sr-1), Φ is the radiant flux or power (W), θ is the angle between the surface normal and the specified direction, A is the area of the source (m2), and Ω is the solid angle (sr). The spectral radiance (radiance per unit wavelength) is written Lλ and the radiance per unit freq ...

See also:

Radiance, Radiance - Definition

Read more here: » Radiance: Encyclopedia II - Radiance - Definition