YPbPr or Y'PbPr written as YPBPR, is a color space used in video electronics, in particular in reference to component video cables. YPbPr is the analog version of the YCbCr color space. YPbPr is referred to as component video by manufacturers; some video cards come with video-in video-out ports for connecting to component video devices. YPbPr is converted from the RGB video signal, split into three components: Y, PB, PR. Y carries synchronization information. Y = 0.2126 R + 0.7152 G + 0.0722 B. Before the advent of color television, the Y axis on an oscilloscope display of a video waveform represented the intensity of the scan line. With color, Y still represents intensity but it is a composite of the component colors. PB carries the difference between luma. PR carries the difference between luma. To send a green signal as a fourth component is redundant, as it can be derived using the blue and luma information; when color signals were first added to the NTSC-encoded black and white video standard, the hue was represented by a phase shift of a color reference sub-carrier.
P for phase information or phase shift has carried through to represent color information in the case where there is no longer a phase shift used to represent hue. Thus, the Y PB PR nomenclature derives from engineering metrics developed for the NTSC color standard; the same cables can be used for composite video. This means that the yellow and white RCA connector cables packaged with most audio/visual equipment can be used in place of the YPbPr connectors, provided the end user is careful to connect each cable to corresponding components at both ends. Many TVs use the green connection either for luma only or for composite video input. Since YPbPr is backwards compatible with the luminance portion of composite video with just component video decoding one can still use composite video via this input, but only luma information will be displayed, along with the chroma dots; the same goes the other way around so long as 576i is used. Signals that use YPbPr offer enough separation that no color multiplexing is needed, so the quality of the extracted image is nearly identical to the signal before encoding.
S-Video and composite video mix the signals together by means of electronic multiplexing. It is possible for their multiplexed counterparts to interfere with each other. Among consumer analog interfaces, only YPbPr and analog RGB component video are capable of carrying non-interlaced video and resolutions higher than 480i or 576i, up to 1080i for YPbPr. Color FAQ, Charles Poynton
Chrominance is the signal used in video systems to convey the color information of the picture, separately from the accompanying luma signal. Chrominance is represented as two color-difference components: U = B′ − Y′ and V = R′ − Y′; each of these difference components may have scale factors and offsets applied to it, as specified by the applicable video standard. In composite video signals, the U and V signals modulate a color subcarrier signal, the result is referred to as the chrominance signal. In digital-video and still-image color spaces such as Y′CbCr, the luma and chrominance components are digital sample values. Separating RGB color signals into luma and chrominance allows the bandwidth of each to be determined separately; the chrominance bandwidth is reduced in analog composite video by reducing the bandwidth of a modulated color subcarrier, in digital systems by chroma subsampling. The idea of transmitting a color television signal with distinct luma and chrominance components originated with Georges Valensi, who patented the idea in 1938.
Valensi's patent application described: The use of two channels, one transmitting the predominating color, the other the mean brilliance output from a single television transmitter to be received not only by color television receivers provided with the necessary more expensive equipment, but by the ordinary type of television receiver, more numerous and less expensive and which reproduces the pictures in black and white only. Previous schemes for color television systems, which were incompatible with existing monochrome receivers, transmitted RGB signals in various ways. In analog television, chrominance is encoded into a video signal using a subcarrier frequency. Depending on the video standard, the chrominance subcarrier may be either quadrature-amplitude-modulated or frequency-modulated. In the PAL system, the color subcarrier is 4.43 MHz above the video carrier, while in the NTSC system it is 3.58 MHz above the video carrier. The NTSC and PAL standards are the most used, although there are other video standards that employ different subcarrier frequencies.
For example, PAL-M uses a 3.58 MHz subcarrier, SECAM uses two different frequencies, 4.250 MHz and 4.40625 MHz above the video carrier. The presence of chrominance in a video signal is indicated by a color burst signal transmitted on the back porch, just after horizontal synchronization and before each line of video starts. If the color burst signal were visible on a television screen, it would appear as a vertical strip of a dark olive color. In NTSC and PAL, hue is represented by a phase shift of the chrominance signal relative to the color burst, while saturation is determined by the amplitude of the subcarrier. In SECAM and signals are transmitted alternately and phase does not matter. Chrominance is represented by the U-V color plane in PAL and SECAM video signals, by the I-Q color plane in NTSC. Digital video and digital still photography systems sometimes use a luma/chroma decomposition for improved compression. For example, when an ordinary RGB digital image is compressed via the JPEG standard, the RGB colorspace is first converted to a YCbCr colorspace, because the three components in that space have less correlation redundancy and because the chrominance components can be subsampled by a factor of 2 or 4 to further compress the image.
On decompression, the Y′CbCr space is rotated back to RGB. Luma Chroma subsampling
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government created by statute to regulate interstate communications by radio, wire and cable. The FCC serves the public in the areas of broadband access, fair competition, radio frequency use, media responsibility, public safety, homeland security; the FCC was formed by the Communications Act of 1934 to replace the radio regulation functions of the Federal Radio Commission. The FCC took over wire communication regulation from the Interstate Commerce Commission; the FCC's mandated jurisdiction covers the 50 states, the District of Columbia, the Territories of the United States. The FCC provides varied degrees of cooperation and leadership for similar communications bodies in other countries of North America; the FCC is funded by regulatory fees. It has an estimated fiscal-2016 budget of US $388 million, it has 1,688 federal employees, made up of 50% males and 50% females as of December, 2017. The FCC's mission, specified in Section One of the Communications Act of 1934 and amended by the Telecommunications Act of 1996 is to "make available so far as possible, to all the people of the United States, without discrimination on the basis of race, religion, national origin, or sex, efficient and world-wide wire and radio communication services with adequate facilities at reasonable charges."
The Act furthermore provides that the FCC was created "for the purpose of the national defense" and "for the purpose of promoting safety of life and property through the use of wire and radio communications."Consistent with the objectives of the Act as well as the 1999 Government Performance and Results Act, the FCC has identified four goals in its 2018-22 Strategic Plan. They are: Closing the Digital Divide, Promoting Innovation, Protecting Consumers & Public Safety, Reforming the FCC's Processes; the FCC is directed by five commissioners appointed by the President of the United States and confirmed by the United States Senate for five-year terms, except when filling an unexpired term. The U. S. President designates one of the commissioners to serve as chairman. Only three commissioners may be members of the same political party. None of them may have a financial interest in any FCC-related business. † Commissioners may continue serving until the appointment of their replacements. However, they may not serve beyond the end of the next session of Congress following term expiration.
In practice, this means that commissioners may serve up to 1 1/2 years beyond the official term expiration dates listed above if no replacement is appointed. This would end on the date that Congress adjourns its annual session no than noon on January 4; the FCC is organized into seven Bureaus, which process applications for licenses and other filings, analyze complaints, conduct investigations and implement regulations, participate in hearings. The Consumer & Governmental Affairs Bureau develops and implements the FCC's consumer policies, including disability access. CGB serves as the public face of the FCC through outreach and education, as well as through their Consumer Center, responsible for responding to consumer inquiries and complaints. CGB maintains collaborative partnerships with state and tribal governments in such areas as emergency preparedness and implementation of new technologies; the Enforcement Bureau is responsible for enforcement of provisions of the Communications Act 1934, FCC rules, FCC orders, terms and conditions of station authorizations.
Major areas of enforcement that are handled by the Enforcement Bureau are consumer protection, local competition, public safety, homeland security. The International Bureau develops international policies in telecommunications, such as coordination of frequency allocation and orbital assignments so as to minimize cases of international electromagnetic interference involving U. S. licensees. The International Bureau oversees FCC compliance with the international Radio Regulations and other international agreements; the Media Bureau develops and administers the policy and licensing programs relating to electronic media, including cable television, broadcast television, radio in the United States and its territories. The Media Bureau handles post-licensing matters regarding direct broadcast satellite service; the Wireless Telecommunications Bureau regulates domestic wireless telecommunications programs and policies, including licensing. The bureau implements competitive bidding for spectrum auctions and regulates wireless communications services including mobile phones, public safety, other commercial and private radio services.
The Wireline Competition Bureau develops policy concerning wire line telecommunications. The Wireline Competition Bureau's main objective is to promote growth and economical investments in wireline technology infrastructure, development and services; the Public Safety and Homeland Security Bureau was launched in 2006 with a focus on critical communications infrastructure. The FCC has eleven Staff Offices; the FCC's Offices provide support services to the Bureaus. The Office of Administrative Law Judges is responsible for conducting hearings ordered by the Commission; the hearing function includes acting on interlocutory requests filed in the proceedings such as petitions to intervene, petitions to enlarge issues, contested discovery requests. An Administrative Law Judge, appointed under the Administrative Procedure Act, presides at the hearing during which documents and sworn testimony are received in evidence, witnesses are cross-examined. At the co
The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help to provide a three dimensional, moving image coloured in daylight. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth; the human eye can differentiate between about 10 million colors and is capable of detecting a single photon. Similar to the eyes of other mammals, the human eye's non-image-forming photosensitive ganglion cells in the retina receive light signals which affect adjustment of the size of the pupil and suppression of the hormone melatonin and entrainment of the body clock; the eye is not shaped like a perfect sphere, rather it is a fused two-piece unit, composed of the anterior segment and the posterior segment. The anterior segment is made up of the cornea and lens; the cornea is transparent and more curved, is linked to the larger posterior segment, composed of the vitreous, retina and the outer white shell called the sclera.
The cornea is about 11.5 mm in diameter, 1/2 mm in thickness near its center. The posterior chamber constitutes the remaining five-sixths; the cornea and sclera are connected by an area termed the limbus. The iris is the pigmented circular structure concentrically surrounding the center of the eye, the pupil, which appears to be black; the size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris' dilator and sphincter muscles. Light energy enters the eye through the cornea, through the pupil and through the lens; the lens shape is controlled by the ciliary muscle. Photons of light falling on the light-sensitive cells of the retina are converted into electrical signals that are transmitted to the brain by the optic nerve and interpreted as sight and vision. Dimensions differ among adults by only one or two millimetres, remarkably consistent across different ethnicities; the vertical measure less than the horizontal, is about 24 mm. The transverse size of a human adult eye is 24.2 mm and the sagittal size is 23.7 mm with no significant difference between sexes and age groups.
Strong correlation has been found between the width of the orbit. The typical adult eye has an anterior to posterior diameter of 24 millimetres, a volume of six cubic centimetres, a mass of 7.5 grams.. The eyeball grows increasing from about 16–17 millimetres at birth to 22.5–23 mm by three years of age. By age 12, the eye attains its full size; the eye is made up of layers, enclosing various anatomical structures. The outermost layer, known as the fibrous tunic, is composed of the sclera; the middle layer, known as the vascular tunic or uvea, consists of the choroid, ciliary body, pigmented epithelium and iris. The innermost is the retina, which gets its oxygenation from the blood vessels of the choroid as well as the retinal vessels; the spaces of the eye are filled with the aqueous humour anteriorly, between the cornea and lens, the vitreous body, a jelly-like substance, behind the lens, filling the entire posterior cavity. The aqueous humour is a clear watery fluid, contained in two areas: the anterior chamber between the cornea and the iris, the posterior chamber between the iris and the lens.
The lens is suspended to the ciliary body by the suspensory ligament, made up of hundreds of fine transparent fibers which transmit muscular forces to change the shape of the lens for accommodation. The vitreous body is a clear substance composed of water and proteins, which give it a jelly-like and sticky composition; the approximate field of view of an individual human eye varies by facial anatomy, but is 30° superior, 45° nasal, 70° inferior, 100° temporal. For both eyes combined visual field is 200 ° horizontal, it is 13700 square degrees for binocular vision. When viewed at large angles from the side, the iris and pupil may still be visible by the viewer, indicating the person has peripheral vision possible at that angle. About 15° temporal and 1.5° below the horizontal is the blind spot created by the optic nerve nasally, 7.5° high and 5.5° wide. The retina has a static contrast ratio of around 100:1; as soon as the eye moves to acquire a target, it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil.
Initial dark adaptation takes place in four seconds of profound, uninterrupted darkness. The process is nonlinear and multifaceted, so an interruption by light exposure requires restarting the dark adaptation process over again. Full adaptation is dependent on good blood flow; the human eye can detect a luminance range of 1014, or one hundred trillion, from 10−6 cd/m2, or one millionth of a candela per square meter to 108 cd/m2 or one hundred million candelas per square meter. This range does not include looking at the midday lightning discharge. At the low end o
Horse racing is an equestrian performance sport involving two or more horses ridden by jockeys over a set distance for competition. It is one of the most ancient of all sports, as its basic premise – to identify which of two or more horses is the fastest over a set course or distance – has been unchanged since at least classical antiquity. Horse races vary in format and many countries have developed their own particular traditions around the sport. Variations include restricting races to particular breeds, running over obstacles, running over different distances, running on different track surfaces and running in different gaits. While horses are sometimes raced purely for sport, a major part of horse racing's interest and economic importance is in the gambling associated with it, an activity that in 2008 generated a worldwide market worth around US$115 billion. Horse racing has a long and distinguished history and has been practised in civilisations across the world since ancient times. Archaeological records indicate that horse racing occurred in Ancient Greece, Babylon and Egypt.
It plays an important part of myth and legend, such as the contest between the steeds of the god Odin and the giant Hrungnir in Norse mythology. Chariot racing was one of the most popular ancient Greek and Byzantine sports. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC and were important in the other Panhellenic Games, it continued although chariot racing was dangerous to both driver and horse, which suffered serious injury and death. In the Roman Empire and mounted horse racing were major industries. From the mid-fifteenth century until 1882, spring carnival in Rome closed with a horse race. Fifteen to 20 riderless horses imported from the Barbary Coast of North Africa, were set loose to run the length of the Via del Corso, a long, straight city street. In times, Thoroughbred racing became, remains, popular with aristocrats and royalty of British society, earning it the title "Sport of Kings". Equestrians honed their skills through games and races. Equestrian sports provided entertainment for crowds and displayed the excellent horsemanship needed in battle.
Horse racing of all types evolved from impromptu competitions between drivers. The various forms of competition, requiring demanding and specialized skills from both horse and rider, resulted in the systematic development of specialized breeds and equipment for each sport; the popularity of equestrian sports through the centuries has resulted in the preservation of skills that would otherwise have disappeared after horses stopped being used in combat. There are many different types of horse racing, including: Flat racing, where horses gallop directly between two points around a straight or oval track. Jump racing, or Jumps racing known as Steeplechasing or, in the UK and Ireland, National Hunt racing, where horses race over obstacles. Harness racing, where horses trot or pace while pulling a driver in a sulky. Saddle Trotting, where horses must trot from a starting point to a finishing point under saddle Endurance racing, where horses travel across country over extreme distances ranging from 25 to 100 miles.
Different breeds of horses have developed. Breeds that are used for flat racing include the Thoroughbred, Quarter Horse, Arabian and Appaloosa. Jump racing breeds include the Thoroughbred and AQPS. In harness racing, Standardbreds are used in Australia, New Zealand and North America, when in Europe and French Trotter are used with Standardbred. Light cold blood horses, such as Finnhorses and Scandinavian coldblood trotter are used in harness racing within their respective geographical areas. There are races for ponies: both flat and jump and harness racing. Flat racing is the most common form of racing seen worldwide. Flat racing tracks are oval in shape and are level, although in Great Britain and Ireland there is much greater variation, including figure of eight tracks like Windsor and tracks with severe gradients and changes of camber, such as Epsom Racecourse. Track surfaces vary, with turf most common in Europe, dirt more common in North America and Asia, newly designed synthetic surfaces, such as Polytrack or Tapeta, seen at some tracks.
Individual flat races are run over distances ranging from 440 yards up to two and a half miles, with distances between five and twelve furlongs being most common. Short races are referred to as "sprints", while longer races are known as "routes" in the United States or "staying races" in Europe. Although fast acceleration is required to win either type of race, in general sprints are seen as a test of speed, while long distance races are seen as a test of stamina; the most prestigious flat races in the world, such as the Prix de l'Arc de Triomphe, Melbourne Cup, Japan Cup, Epsom Derby, Kentucky Derby and Dubai World Cup, are run over distances in the middle of this range and are seen as tests of both speed and stamina to some extent. In the most prestigious races, horses are allocated the same weight to carry for fairness, with allowances given to younger horses and female horses running against males; these races offer the biggest purses. There is another category of races called handicap races where each horse is assigned a different weight to carry based on its ability.
Beside the weight they carry, horses' performance can be influenced by position relative to the inside barrier, gender and training. Jump racing in Gr
AM stereo is a term given to a series of mutually incompatible techniques for radio broadcasting stereo audio in the AM band in a manner, compatible with standard AM receivers. There are two main classes of systems: independent sideband systems, promoted principally by American broadcast engineer Leonard R. Kahn. Adopted by many commercial AM broadcasters in the mid to late 1980s, AM stereo broadcasting soon began to decline due to a lack of receivers, a growing exodus of music broadcasters to FM, concentration of ownership of the few remaining stations in the hands of large corporations and the removal of music from AM stations in favour of news/talk or sports broadcasting. By 2001, most of the former AM stereo broadcasters were no longer stereo or had left the AM band entirely. Early experiments with stereo AM radio involved two separate stations broadcasting the left and right audio channels; this system was not practical, as it required the listener to use two separate receivers. Synchronization was problematic resulting in "ping-pong" effects between the two channels.
Reception was likely to be different between the two stations, many listeners used mismatching models of receivers. After the early experiments with two stations, a number of systems were invented to broadcast a stereo signal in a way, compatible with standard AM receivers. FM stereo was first implemented in 1961. In the United States, FM overtook AM as the dominant broadcast radio band in the late 1970s and early 1980s. 1924: WPAJ broadcast in stereo from New Haven, using two transmitters: one on 1120 kHz and the other on 1320 kHz. However stereo separation was poor. In the 1950s, several AM stereo systems were proposed but the FCC did not propose any standard as AM was still dominant over FM at the time. 1960: AM stereo first demonstrated on XETRA-AM, Mexico, using the Kahn independent sideband system. 1963: WHAZ runs a stereo program on eight AM stations, four on each channel. 1980: After five years of testing the five systems, the United States Federal Communications Commission selected the Magnavox system as the official AM stereo standard.
The FCC's research is accused of being flawed and incomplete. 1982: After a series of lawsuits and accusations, the FCC decides to let the marketplace decide and revokes the Magnavox certification as the AM stereo standard for political reasons. Belar had dropped out of the AM stereo race due to receiver distortion problems, leaving Motorola C-QUAM, Harris Corporation and the Kahn/Hazeltine independent sideband system. 1984: General Motors, Chrysler, a number of import automakers begin installing C-QUAM AM stereo receivers in automobiles, beginning with the 1985 model year. Harris Corporation abandons its AM stereo system and puts its support behind C-QUAM. 1985: AM stereo broadcasting begins in Australia, with the C-QUAM standard. 1988: Canada and Mexico adopt C-QUAM as their standard for AM stereo. 1992: Japan adopts C-QUAM as its standard for AM stereo. 1993: The FCC makes C-QUAM the AM stereo standard for stations in the U. S. and grants "stereo preference" for radio stations requesting to move to the AM expanded band, although such stations have never been required to transmit in stereo.
1993: The AMAX certification program begins. This was to set an official manufacturing standard for high-quality AM radio receivers, with a wider audio bandwidth for higher fidelity reception of strong signals, optionally C-QUAM AM stereo. Despite the availability of AMAX receivers from companies like Sony, General Electric, AMAX-certified car radios from the domestic and Japanese automakers, most electronics manufacturers did not wish to implement the more costly AMAX tuner design in their radios, so most AM radios today remain in mono with limited fidelity. 2006 to present: AM stereo gains new life through the support for C-QUAM decoding in most receivers designed for HD Radio. These new digital radios receive AM stereo signals, although the AM transmitters are now limited to 10 kHz audio bandwidth and the HD receivers flip Left and Right channels in decoding C-QUAM stereo; the Magnavox PMX, Harris Corporation V-CPM, Motorola C-QUAM were all based around modulating the phase and amplitude of the carrier, placing the stereo information in the phase modulated portion, while the standard mono information is in the amplitude modulation.
The systems all did this in similar ways. The original Harris Corporation system was changed to match the Motorola C-QUAM pilot tone for indicating the station was in stereo, thus making it compatible with all C-QUAM receivers; this system, known as V-CPM for Variable Angle Compatible Phase Multiplex, was developed by Harris Corporation, a major manufacturer of radio/TV transmitters. It incorporated a left minus right component, frequency modulated by about 1 kHz. Harris is the successor to the pioneer Gates radio line, which has changed its name in 2014 to Gates-Air; the Harris system changed their pilot tone to be compatible with C-QUAM, after C-QUAM became the more popular and the FCC approved standard. CKLW in Windsor, Canada was among the first stations to broadcast in Harris AM stereo; the Harris system is currentl