This article relates to birds. For clipped-wing aircraft, see Wing. Wing clipping is the process of trimming a bird's primary wing feathers or remiges so that it is no longer flighted. Wing clipping is performed by avian veterinarians, pet store employees, breeders, or the birds' owners themselves, it is carried out on pet birds parrots. If performed it is a painless procedure and is quite distinct from pinioning, carried out by amputation of the wing at the carpal joint. Techniques for clipping the wings vary in the number of feathers cut and the amount of each feather left behind. A mild clip on one wing only can impair a bird's flight as it renders the bird unbalanced in the air; this can cause death to the bird if it strikes a hard surface during a fall. In most cases, it is only the primary flight feathers that are cut, an equal number of feathers are trimmed on each wing to avoid causing the bird to become unbalanced in flight; the most common clip involves trimming the primary flight feathers below the level of the primary coverts.
This clip is quick and simple to do, but leaves exposed cut ends that may cause a bird to chew on the cut feathers. Another method of clipping involves cutting the flight feather above the level of the coverts, so the entire feather is removed; this clip does not leave any exposed cut ends, but as more of each feather is removed, fewer feathers should be cut. However, these cut feather stumps are still present and may irritate the bird, causing significant discomfort. Where parrots have clipped primary feathers, the moulting sequence of these birds renders them vulnerable to damage of their growing blood feathers. Most parrots have 10 primary feathers, numbered 1 to 10; the moult starts by the bird shedding and replacing a central primary feather number 6. The sequence continues in both directions along the primaries, so the last primary feathers to be replaced are the innermost and the outermost ones numbered 1 and 10 respectively. Clipped birds therefore have their first blood feathers growing down without the normal protection of full-length feathers lying next to them.
These unprotected blood feathers are vulnerable to being broken and profuse bleeding can occur. Regardless of their size, most parrots replace their feathers by a daily growth rate of 3 to 4 mm Thus, large species such as macaws may take over a year to complete a moult, but smaller species such as cockatiels will moult within a few weeks. So, larger birds, those with a higher wing-loading, remain vulnerable to blood feather damage for a longer period, since they are moulting continually. A'light' symmetrical wing-clip will allow a bird to land safely while indoors; however such a clip may not prevent the bird from flying when outdoors, since lift is generated in proportion to wind speed. Many escaped birds which are recovered are found to have been clipped. So, while a light clip allows downward flight indoors, it does not prevent a bird gaining lift if it should escape outdoors. Conversely, a more severe clip will render a bird flightless, but it increases the risk of injury if the bird falls and hits a hard surface.
In addition to the physical effects of wing-clipping, there can be adverse behavioural effects. Birds use flight as an instinctive reflex action and as their first means of escaping any threat: they take to the air to fly upwards and away from the source of the threat. Where this behaviour is prevented by wing-clipping, this innate reflex action is denied the bird, its fear will not subside; this may cause behavioural problems for the afflicted bird. When a bird needs to reduce its speed during flight, it employs a'reverse thrust' action by extending its wing at the wrist joint and using the drag of its primaries as air brakes. While the reduced function of the clipped bird's primaries prevent propulsion and therefore lift, this reduces braking abilities, so clipped birds may crash-land at higher speeds than full-winged birds. Clipped birds should not be taken outdoors unrestrained, as clipped birds have been known to fly away when spooked outdoors, it is considered important for a young bird to be allowed to fledge properly, prior to any wing clipping.
Breeders and owners find that a fledged bird after being clipped, will remain more confident and active than an unfledged bird. Learning to fly helps a bird learn how to land safely, an important skill in clipped birds. While clipping is endorsed by some avian veterinarians, other avian veterinarians oppose it. By restricting flight, wing clipping may help prevent indoor birds from risking injury from ceiling fans or flying into large windows, but there is no evidence to show that clipped birds are safer than full-winged ones, only that clipped birds are subject to different kinds of accidents than full-winged birds. Social pet birds may be clipped both to restrict independence and in attempts to make them tamer and easier to manage in order to encourage them to socialize with their owners. However, birds can be trained to accept flight requests or'commands' and this removes the need for wing-clipping; some people feel wing clipping is a cruel or unhealthy practice as it denies a bird its most natural way of getting around, obtaining exercise and avoiding fearful situations.
Although clipped birds can and should be encouraged to do wing flapping exercises, this does no
Sheep shearing is the process by which the woollen fleece of a sheep is cut off. The person who removes the sheep's wool is called a shearer; each adult sheep is shorn once each year. The annual shearing most occurs in a shearing shed, a facility designed to process hundreds and sometimes more than 3,000 sheep per day. Sheep are shorn in all seasons, depending on the climate, management requirements and the availability of a woolclasser and shearers. Ewes are shorn prior to lambing, but consideration is made as to the welfare of the lambs by not shearing during cold climate winters. Shorn sheep tolerate frosts well, but young sheep will suffer in cold, wet windy weather. In this event they are shedded for several nights; some sheep may be shorn with stud combs which leave more wool on the animal, giving greater protection. Sheep shearing is considered a sport with competitions held around the world, it is done between spring and summers The wealth of ancient Knossos, Europe's oldest city, derived from its sheep wool industry.
The largest group of Linear B tablets is the great archive principally of shearing records though of sheep breeding. The medieval English wool trade was one of the most important factors in the English economy; the main sheep-shearing was an annual midsummer event in medieval England culminating in the sheep-shearing feast. It had always been conventional practice to wash sheep. Australia's fine woolsIn Australia, until the 1870s, squatters washed their sheep in nearby creeks prior to shearing; some expensive hot water installations were constructed on some of the larger stations for the washing. Australian growers were influenced by the Spanish practice of washing their fine wool after shearing. There were three main reasons for the custom in Australia: The English manufacturers demanded that Australian woolgrowers provide their fleeces free from excessive vegetable matter, soil, etc. so they could be processed in the same way as any other raw wool The dirty fleeces were hard to shear and demanded that the metal blade shears be sharpened more often.
Wool in Australia was charged by weight. Washed wool did not cost as much to transport; the practice of washing the wool rather than the sheep evolved from the fact that hotter water could be used to wash the wool, than that used to wash the sheep. When the practice of selling wool in the grease occurred in the 1890s, wool washing became obsolete. Australia and New Zealand had to discard the old methods of wool harvesting and evolve more efficient systems to cope with the huge numbers of sheep involved. Shearing was revolutionized by the invention of Frederick York Wolseley, his machines made in Birmingham, England, by his business The Wolseley Sheep Shearing Machine Company were introduced after 1888, reducing second cuts and shearing time. By 1915 most large sheep station sheds in Australia had installed machines, driven by steam or by internal combustion engines. Shearing tables were invented in the 1950s and have not proved popular, although some are still used for crutching. In the US, the worldwide shortage of shearers is becoming a consideration for those wanting to expand wool production.
With sheep numbers declining in that country the profession sees less interest in becoming a qualified shearer. Importing labour during the Australian off-season has become problematic because of delays in obtaining work visa and because shearers numbers are limited worldwide. Today large flocks of sheep are mustered and treated for parasites such as lice before shearing can start. Then shorn by professional shearing teams working eight-hour days, most in spring, by machine shearing; these contract-teams consist of shed hands and a cook. Their working hours and wages are regulated by industry awards. A working day starts at 7:30 am and the day is divided into four "runs" of two hours each. "Smoko" breaks are a half-hour each and a lunch break is taken at midday for one hour. Most shearers are paid on a piece-rate per sheep. Shearers who "tally" more than 200 sheep per day are known as "gun shearers". Typical mass shearing of sheep today follows a well-defined workflow: remove the wool throw the fleece onto the wool table skirt and class the fleece place it in the appropriate wool bin press and store the wool until it is transported.
In 1984 Australia became the last country in the world to permit the use of wide combs, due to previous Australian Workers' Union rules. Although they were once rare in sheds, women now take a large part in the shearing industry by working as pressers, wool rollers, wool classers and shearers. A sheep is caught by the shearer, from the catching pen, taken to his "stand" on the shearing board, it is shorn using a mechanical handpiece. The wool is removed by following an efficient set of movements, devised by Godfrey Bowen in about 1950 or the Tally-Hi method developed in 1963 and promoted by the Australian Wool Corporation. Sheep struggle less using the Tally-Hi method, reducing strain on the shearer and there is a saving of about 30 seconds in shearing each one; the shearer begins by removing the belly wool, separated from the main fleece by a rouseabout, while the sheep is still being shorn. A professional or "gun" shearer removes a fleece, without marking or cutting the sheep, in two to three minutes, depending on the size and condition of the sheep—less than two minutes in elite-comp
Horse grooming is hygienic care given to a horse, or a process by which the horse's physical appearance is enhanced for horse shows or other types of competition. Grooming is an important part of horse care. Grooming a horse daily allows the handler to check on horse's general health and well-being. At a minimum, horses are groomed before being worked, are groomed and cleaned up after a workout as well; the main reasons for daily grooming include: Improved health of the skin and coat Decreases the chance of various health problems such as thrush and other skin problems Cleans the horse, so chafing does not occur under areas of tack Gives the groom a chance to check the horse's health, such as looking for cuts, swelling, lameness, a change in temperament which could indicate the horse is sick, look to see if the horse has loose or missing horseshoes Helps to form a relationship between horse and handler, which can carry over to other handling duties and ridingHorse showmanship is a horse show class that considers quality of grooming for as much as 40% of the total score.
There are several tools that are used when grooming a horse. Proper use and technique helps to ensure the horse remains comfortable during the grooming process, allows for greater ease in cleaning the animal. Curry or Curry comb: A tool made of rubber or plastic with short "teeth" on one side, that slides onto the hand of the groom, it is the first tool used in daily grooming. The horse is rubbed or "curried" to help loosen dirt and other detritus, plus stimulate the skin to produce natural oils; the curry comb is used in a circular motion to work loose embedded material. Alternately you can use a multiple short. Curry combs are too harsh to be used on the legs or head, though varieties made of softer rubber are available. Metal curry comb or Fitch curry comb: It is a curry comb made of several rows of short metal teeth, with a handle. While useful for caked-on mud on horses with a heavy winter coat, they are designed for use on show cattle, are used to clean horse grooming brushes by moving the brush across the metal curry comb teeth every few strokes.
The metal curry comb is not designed for use directly on the summer coat of a horse as the metal teeth can damage the skin and hair. Not to be confused with the shedding blade, below. Hard-bristled brush: A stiff-bristled brush is used to remove the dirt and other material stirred up by the curry. Brushes are used in the direction of the horse's hair coat growth in short strokes from front to back, except at the flanks, where the hair grows in a different pattern; the best quality dandy brushes are made of stiff natural bristles such as rice stems, though they wear out quickly. Plastic-bristled dandy brushes are more common. Dandy brushes can be used on the legs, but many horses object to a stiff brush being used on the head; some dandy brushes do double duty as a Water Brush, when moistened in water and used to wet down the hair coat, mane or tail. Such use may include creating quarter marks for show. Body brush or Soft brush or "Dandy Brush": A soft-bristled brush removes finer particles and dust, adds a shine to the coat and is soothing to the horse.
A body brush a smaller design called a Face brush, can be used on the head, being careful to avoid the horse's eyes. Some natural body brushes are made of horsehair, goat hair or boar bristles, like human hairbrushes, others are made of soft synthetic fibers; the body brush is the last brush used on the horse. Grooming rag or towel called a Stable rubber: A linen or terrycloth towel or similar type of cloth, or sheepskin mitt, can be used to give a final polish to a horse's coat and is used after riding to help remove sweat. Mane brush or comb: Horses with short, pulled manes have their manes combed with a wide-toothed plastic or metal comb. Tails and long manes are brushed with either a suitable human hairbrush. Long show-quality manes and tails are picked out by hand to avoid breaking the hairs. A short-toothed Pulling comb is used to pull the mane to shorten and thin it in preparation for braiding. Hoof pick: A hooked tool of metal, used to clean the hooves of a horse; some designs include a small stiff brush for removing additional mud or dirt.
All four feet of the horse need to be cleaned out after riding. Shedding blade: In special weather conditions, a metal shedding blade with short, dull teeth is used to remove loose winter hair. A shedding blade is useful for removing caked-on mud. However, grooming tools with metal teeth can split and dull the horse's hair coat and may irritate the skin, so must be used with appropriate care. Metal grooming tools used on sheep and show cattle may be too harsh to use on a horse. Sweat scraper: Several styles of sweat scraper exist to remove sweat after exertion or water after bathing. One is plastic wand, about 18 inches long. Another design is an arc of plastic or rubber attached to a handle, sometimes with two curved blades attached back to back. A third design is a flexible curved blade with teeth on one side to use as a shedding blade, smooth on the other, for use as a sweat scraper. Fly spray: In the summer, fly spray is applied to the horse after grooming. Care must be taken to avoid the mucous membranes.
Bot knife or Bot brick: used to remove botfly eggs from the horse, which are laid on the legs or shoulder. Bot eggs are yellow and the size of a grain of sand, they are visible
In digital photography and digital video, clipping is a result of capturing or processing an image where the intensity in a certain area falls outside the minimum and maximum intensity which can be represented. It is an instance of signal clipping in the image domain; the clipped area of the image will appear as a uniform area of the minimum or maximum brightness, losing any image detail. The amount by which values were clipped, the extent of the clipped area, affect the degree to which the clipping is visually noticeable or undesirable in the resulting image. In a color image, clipping may occur in any of the image's color channels separately. Clipping can occur at many different stages, it may occur in the image sensor when capturing the image using a digital camera or scanner. It may occur due to internal image color space conversion in the camera or scanner, it may result from image processing using image editing software. Clipping, due to internal image processing in a digital camera may be or recovered if the raw sensor data is available, such as when saving to a raw image format.
Clipping can occur in image highlights as a result of an incorrect exposure when photographing or scanning to a digital image. Increasing an exposure increases the amount of light collected or the sensitivity of the sensor, increasing it too far will cause the lightest areas, such as the sky, or light sources, to clip. Bright areas due to overexposure are sometimes called blown-out flared highlights. In extreme cases, the clipped area may appear to have a noticeable border between the clipped and non-clipped area; the clipped area will be white, though in the case that only one color channel has clipped, it may represent itself as an area of distorted color, such as an area of sky, greener or yellower than it should be. A similar effect of blown-out highlights exists in analog photography, though in that case it is not referred to as "clipping", the "blown-out" area curves off to its maximum brightness rather than being cut off abruptly as in clipping; this causes blown-out highlights to appear differently in analog and digital photography, with the smooth edges in analog photography regarded as more pleasant to some.
In some cases, a small amount of clipping may be tolerable when the clipped area is in the background of the image rather than part of the main subject, or is only a small area such as a specular highlight. Clipping in some color channels may occur when an image is rendered to a different color space, when the image contains colors that fall outside the target color space; such colors are referred to as out-of-gamut. This form of clipping may be avoided by performing the color space conversion using a different rendering intent. However, this can sometimes result in a lower overall color saturation; the desire for bright, saturated colors may, in some cases, be more important than avoiding clipping in single channels due to out-of-gamut colors. Clipping may occur in digital video, just as in digital still photography. Just as with digital still photography, an intensity value, outside the allowed range of values in any one channel causes clipping. High dynamic range Graduated neutral density filter What is white or black "clipping", how does one avoid it?
Understanding Digital Camera Histograms: Tones and Contrast
In some video games, noclip mode is a video game cheat command that prevents the first-person player character camera from being obstructed by other objects and permits the camera to move in any direction, allowing it to pass through such things as walls and other players. Noclipping can be used to cheat, avoid bugs, find easter eggs, view areas beyond a map's physical boundary; the term was popularized by the games of id Software in the 1990s. The name is derived from the command traditionally used to activate it: typing "idclip" in the game's command PC game console for Doom II; the cheat is commonplace in action-oriented first-person shooters such as Quake or Half-Life. John Carmack of id Software has told fans that he derived the term from the concept of "clipping a movement vector"; the first instance of noclip code came from id Software's popular game series Commander Keen. Noclip modes originate as a means by which developers test games. If a new feature is implemented in a game but requires play to determine whether it works, it saves time if a developer can reach the relevant portion of the game by avoiding death or by "flying" over time-consuming regions of the game environment.
This source of god modes manifests itself in the route by which players activate these modes – for example, running a game with a development mode flag. The equivalent code for a game may turn off clipping, but this is not the reason why the player can walk through walls; the code turns off collision detection, an separate toggle. The code does not turn off back-face culling, why the other side of a one-sided wall is not drawn when the player uses "no collision" mode to walk through it; some developers have continued in the fashion of id Software. Speaking and objects have no "substance" unless advanced in-game physics is being used. Collision detection object with the player's avatar. If there is an intersection, the game stops the player's motion, as if they had bumped into the intersecting object. Otherwise, the avatar will pass through it; this is a simple method of implementing in-game physics with walls. Noclipping can conflict with other elements of the game. For instance, in the MS-DOS registered 1.3D version of Duke Nukem 3D, the Commander Keen series, having noclip mode on and walking outside the level area causes death, if the player has god mode activated the game will be left in an infinite loop or crash due to the way god mode was implemented.
In the MS-DOS Plutonium Pak 1.4 / Atomic Edition 1.5 and in source ports for Duke Nukem 3D, this problem is corrected and it instead behaves more like Doom. Disabling collision detection may interfere with the game's programming in other ways. In the classic first-person shooter Doom, an effect known as the'Hall of Mirrors' can occur as a result of design error or player experimentation. Games of the day had been programmed under the assumption that the player's viewpoint would always be contained within sealed areas; this made it unnecessary to erase the contents of the screen before drawing the next frame. However, when the player used noclip mode to maneuver the virtual camera so as to violate this assumption, the game would generate frames with "holes" in them where there was no content to display; these frames would fail to cover the older ones, leaving whatever had been drawn a moment before still visible in certain regions of the screen. As the player further moved the virtual camera, numerous un-erased regions would blend together to produce visual patterns resembling those encountered in a physical hall of mirrors.
Typing gl_clear 1 in Quake engine games is a way to empty the buffer of the image of what was last rendered. With this setting, a magenta color is drawn outside of the world, clearing the screen and aiding navigation when outside of the level. There are bugs in games such as Sonic Adventure 2, Dead Rising, Lost Planet and We Love Katamari at which the character's shadow appears on all floors below the character instead of only the floor beneath the character; this can happen in Source engine games including Half-Life 2, Counter-Strike: Source, Left 4 Dead, Team Fortress 2, where if a mapmaker has not set the correct properties on a floor, the shadows of the players above will show through. This is not helpful in the least for players in upper rooms trying to hide or avoid detection from players below them. In Team Fortress 2, no clipping can be used to build buildings in spawns. In Counter-Strike and the Left 4 Dead series, after the player has died, they have the option to select "free mode" as they wait to respawn or are a spectator.
This allows the player to move anywhere on the map. This ability helps to find secret areas of the map that are unreachable or unable to be seen in normal play such as seeing the credits for the map de_Dust2 outside the Counter Terrorist's spawn; this can happen in Unity games if the camera's Clear Flags are set to "Don't Clear". In many Unreal Engine games there are several cheats; the most common one is a single typing of the ghost cheat. The player typing the cheat will be able to fly around the level
Clipping is a form of waveform distortion that occurs when an amplifier is overdriven and attempts to deliver an output voltage or current beyond its maximum capability. Driving an amplifier into clipping may cause it to output power in excess of its power rating; when an amplifier is pushed to create a signal with more power than its power supply can produce, it will amplify the signal only up to its maximum capacity, at which point the signal can be amplified no further. As the signal "cuts" or "clips" at the maximum capacity of the amplifier, the signal is said to be "clipping"; the extra signal, beyond the capability of the amplifier is cut off, resulting in a sine wave becoming a distorted square-wave-type waveform. Amplifiers have voltage and thermal limits. Clipping may occur due to limitations in the output stage; some amplifiers are able to deliver peak power without clipping for short durations before energy stored in the power supply is depleted or the amplifier begins to overheat.
The higher frequency harmonics generated by an amplifier operating in clipping can damage a connected loudspeaker. This additional high frequency energy has the potential to damage a tweeter via overheating; as a result, many amplifier designers have incorporated circuits to prevent clipping. The simplest circuits act like a fast limiter, which engages about one decibel before the clipping point. A more complex circuit, called "soft-clip", has been used from the 1980s onward to limit the signal at the input stage; the soft-clip feature begins to engage prior to clipping, for instance starting at 10 dB below maximum output power. The output waveform retains a rounded characteristic in the presence of an overload input signal as much as 10 dB higher than maximum specified. In digital signal processing, clipping occurs when the signal is restricted by the range of a chosen representation. For example, in a system using 16-bit signed integers, 32767 is the largest positive value that can be represented.
If, during processing, the amplitude of the signal is doubled, sample values of, for instance, 32000 should become 64000, but instead cause an integer overflow and saturate to the maximum, 32767. Clipping is preferable to the alternative in digital systems—wrapping—which occurs if the digital processor is allowed to overflow, ignoring the most significant bits of the magnitude, sometimes the sign of the sample value, resulting in gross distortion of the signal; the simplest way to avoid clipping is to reduce the signal level. Alternatively the system can be improved to support higher signal level without clipping. A limiter can be used to dynamically bring the levels of the loud parts of a signal down. Clipping can occur within a system as processing can change the phase relationship between spectral components of a signal in such a way as to create excessive peak outputs; the excessive peaks may become clipped though the system can play any simple sine wave signals of the same level without clipping.
As such, some audiophiles will use amplifiers that are rated for power outputs over twice the speaker's ratings. It is preferable to avoid clipping, but if a recording has clipped, cannot be re-recorded, repair is an option; the goal of repair is to make up a plausible replacement for the clipped part of the signal. Complex hard-clipped signals cannot be restored to their original state because the information contained in the peaks that are clipped is lost. Soft-clipped signals can be restored to their original state to within a case-dependent tolerance because no part of the original signal is lost. In this case, the degree of information loss is proportional to the degree of compression caused by the clipping. Clipped bandwidth-limited signals that are oversampled have the potential for perfect repair. Several methods can restore a clipped signal. Once the clipped portion is known, one can attempt partial recovery. One such method is extrapolation of known samples. Advanced implementations may use cubic splines to attempt to restore a continuously differentiable signal.
While these reconstructions are only an approximation of the original, the subjective quality may be improved. Other methods include copying the signal directly from one stereo channel to another, as it may be the case that only one channel is clipped. Several software solutions of varying results and methods exist to repair clipping: CuteStudio Declip, Sony Sound Forge, iZotope Rx3, iZotope Rx7, Adobe Audition, Nero Wave Editor, declipping solutions from CEDAR Audio, Audacity plugins such as Clip Fix. In analog audio equipment, there are several causes of clipping: The peak-to-peak output of a solid-state transformerless amplifier is limited by the power supply voltage. An amplifier may have an asymmetrical output swing and clipping may begin earlier on one half of the output waveform. If the power supply filter capacitor is unable to support the voltage due to a massive current draw from the amplifier, the voltage supply to the amplifier will fluctuate resulting in sort of a clipped signal that contains some AC line frequency harmonics.
A vacuum tube can only move a limited number of electrons in a given amount of time, dependent on its size and metals. The resulting fall-off in amplification with increasing output current results in soft clipping. Amplifying devices may have limits on their inputs, for example excessive base current to a bipolar transistor or excessive grid current to a vacuum tube. Operating outside these limits can distort the input signal, if it comes from a high enough impedance source, or damage the amplifying device requiring a limiting circuit for protection. An amplifier ma
Clipping (signal processing)
Clipping is a form of distortion that limits a signal once it exceeds a threshold. Clipping may occur when a signal is recorded by a sensor that has constraints on the range of data it can measure, it can occur when a signal is digitized, or it can occur any other time an analog or digital signal is transformed in the presence of gain or overshoot and undershoot. Clipping may be described as hard, in cases where the signal is limited at the threshold, producing a flat cutoff. Hard clipping results in many high frequency harmonics. In the audio domain, clipping may be heard as pops; because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power than its rated output when it is clipping. This extra power can damage any part of the loudspeaker, including the woofer, or the tweeter, by causing over-excursion, or by overheating the voice coil, it may cause damage to the amplifier's power supply or blow a fuse. In the frequency domain, clipping produces strong harmonics in the high frequency range.
The extra high frequency weighting of the signal could make tweeter damage more than if the signal was not clipped. However most loudspeakers are designed to handle signals like cymbal crashes that have more high frequency weighting than amplifier clipping produces, so damage attributable to this characteristic is rare. Many electric guitar players intentionally overdrive their amplifiers to cause clipping in order to get a desired sound; some audiophiles believe that the clipping behavior of vacuum tubes with little or no negative feedback is superior to that of transistors, in that vacuum tubes clip more than transistors, resulting in harmonic distortion, less objectionable. In general though, the distortion associated with clipping is unwanted, is visible on an oscilloscope if it is inaudible. In a transistorised amplifier with hard clipping, the gain of the transistor will be reducing as the output current increases and the voltage across the transistor reduces close to the saturation voltage, so "full power" for the purposes of measuring distortion in amplifiers is taken as a few percent below clipping.
In the image domain, clipping is seen as desaturated bright areas that turn to pure white if all color components clip. A circuit designer may intentionally use a clipper or clamper to keep a signal within a desired range; when an amplifier is pushed to create a signal with more power than it can support, it will amplify the signal only up to its maximum capacity, at which point the signal will be amplified no further. An integrated circuit or discrete solid state amplifier cannot give an output voltage larger than the voltage it is powered by. A vacuum tube can only move a limited number of electrons in an amount of time, dependent on its size and metals. A transformer will clip. In digital signal processing, clipping occurs when the signal is restricted by the range of a chosen representation. For example in a system using 16-bit signed integers, 32767 is the largest positive value that can be represented, if during processing the amplitude of the signal is doubled, sample values of 32000 should become 64000, but instead they are truncated to the maximum, 32767.
Clipping is preferable to the alternative in digital systems — wrapping — which occurs if the digital hardware is allowed to "overflow", ignoring the most significant bits of the magnitude, sometimes the sign of the sample value, resulting in gross distortion of the signal. The incidence of clipping may be reduced by using floating point numbers instead of integers. However, floating point numbers are less efficient to use, sometimes result in a loss of precision, they can still clip if a number is large or small. Clipping can be detected by viewing the signal, observing that the tops and bottoms of waves aren't smooth anymore; when working with images, some tools can highlight all pixels that are pure white, allowing the user to identify larger groups of white pixels and decide if too much clipping has occurred. To avoid clipping, the signal can be dynamically reduced using a limiter. If not done this can still cause undesirable distortion, but it prevents any data from being lost; when clipping occurs, part of the original signal is lost, so perfect restoration is impossible.
Thus, it is much preferable to avoid clipping in the first place. However, when repair is the only option, the goal is to make up a plausible replacement for the clipped part of the signal. Dynamic range Dynamic range compression Clipping