64-450: Dolby Laboratories, Inc. (often shortened to Dolby Labs and known simply as Dolby ) is a British-American technology corporation specializing in audio noise reduction , audio encoding/compression , spatial audio, and HDR imaging. Dolby licenses its technologies to consumer electronics manufacturers. Dolby Labs was founded by Ray Dolby (1933–2013) in London , England, in 1965. In
128-483: A Dolby-encoded optical soundtrack. In 1975, Dolby released Dolby Stereo , which included a noise reduction system in addition to more audio channels (Dolby Stereo could actually contain additional center and surround channels matrixed from the left and right). The first film with a Dolby-encoded stereo optical soundtrack was Lisztomania (1975), although this only used an LCR (Left-Center-Right) encoding technique. The first true LCRS (Left-Center-Right-Surround) soundtrack
192-440: A company they perceive as possibly lacking liquidity. For example, if all shareholders were to simultaneously try to sell their shares in the open market, this would immediately create downward pressure on the price for which the share is traded unless there were an equal number of buyers willing to purchase the security at the price the sellers demand. So, sellers would have to either reduce their price or choose not to sell. Thus,
256-663: A de-emphasis process applied at playback. Systems include the professional systems Dolby A and Dolby SR by Dolby Laboratories , dbx Professional and dbx Type I by dbx , Donald Aldous' EMT NoiseBX, Burwen Noise Eliminator [ it ] , Telefunken 's telcom c4 [ de ] and MXR Innovations' MXR as well as the consumer systems Dolby NR , Dolby B , Dolby C and Dolby S , dbx Type II , Telefunken's High Com and Nakamichi 's High-Com II , Toshiba 's (Aurex AD-4) adres [ ja ] , JVC 's ANRS [ ja ] and Super ANRS , Fisher / Sanyo 's Super D , SNRS , and
320-400: A de-emphasis process applied during playback. Modern digital sound recordings no longer need to worry about tape hiss so analog-style noise reduction systems are not necessary. However, an interesting twist is that dither systems actually add noise to a signal to improve its quality. Dual-ended compander noise reduction systems have a pre-emphasis process applied during recording and then
384-521: A decoder. The Telefunken High Com integrated circuit U401BR could be utilized to work as a mostly Dolby B –compatible compander as well. In various late-generation High Com tape decks the Dolby-B emulating D NR Expander functionality worked not only for playback, but, as an undocumented feature, also during recording. dbx was a competing analog noise reduction system developed by David E. Blackmer , founder of Dbx, Inc. It used
448-401: A long period of time after maturity into a profitable company. However, from 1997 to 2012, the number of corporations publicly traded on US stock exchanges dropped 45%. According to one observer ( Gerald F. Davis ), "public corporations have become less concentrated, less integrated, less interconnected at the top, shorter lived, less remunerative for average investors, and less prevalent since
512-415: A major type of noise is hiss created by random electron motion due to thermal agitation. These agitated electrons rapidly add and subtract from the output signal and thus create detectable noise . In the case of photographic film and magnetic tape , noise (both visible and audible) is introduced due to the grain structure of the medium. In photographic film, the size of the grains in the film determines
576-456: A root-mean-squared (RMS) encode/decode algorithm with the noise-prone high frequencies boosted, and the entire signal fed through a 2:1 compander. dbx operated across the entire audible bandwidth and unlike Dolby B was unusable without a decoder. However, it could achieve up to 30 dB of noise reduction. Since analog video recordings use frequency modulation for the luminance part (composite video signal in direct color systems), which keeps
640-553: A separate entity, its former shareholders receiving compensation in the form of either cash, shares in the purchasing company or a combination of both. When the compensation is primarily shares then the deal is often considered a merger . Subsidiaries and joint ventures can also be created de novo . That often happens in the financial sector. Subsidiaries and joint ventures of publicly traded companies are not generally considered to be privately held companies (even though they themselves are not publicly traded) and are generally subject to
704-523: A stock exchange ( listed company ), which facilitates the trade of shares, or not ( unlisted public company ). In some jurisdictions, public companies over a certain size must be listed on an exchange. In most cases, public companies are private enterprises in the private sector, and "public" emphasizes their reporting and trading on the public markets. Public companies are formed within the legal systems of particular states and so have associations and formal designations, which are distinct and separate in
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#1732765630973768-419: A type of artificial noise, if the noise spectrum estimate is inaccurate. Applications: Primarily used in audio signal processing, including mobile telephony and hearing aids. Advantages: Simple to implement and computationally efficient. Limitations: Tends to perform poorly in the presence of non-stationary noise, and can introduce artifacts. Adaptive filters are highly effective in situations where noise
832-438: A variety of sources. Further use of these images will often require that the noise be reduced either for aesthetic purposes, or for practical purposes such as computer vision . Public company A public company is a company whose ownership is organized via shares of stock which are intended to be freely traded on a stock exchange or in over-the-counter markets. A public (publicly traded) company can be listed on
896-497: Is a statistical approach to noise reduction that minimizes the mean square error between the desired signal and the actual output. This technique relies on knowledge of both the signal and noise power spectra, and it can provide optimal noise reduction if these spectra are accurately estimated. Applications: Frequently applied in image processing, audio restoration, and radar. Advantages: Provides optimal noise reduction for stationary noise. Limitations: Requires accurate estimates of
960-575: Is an advanced noise reduction technique that uses redundancy in the signal by averaging similar patches across the signal or image. While computationally more demanding, NLM is highly effective in removing noise from images and audio signals without blurring. Applications: Applied primarily in image denoising, especially in medical imaging and photography. Advantages: Preserves details and edges in images. Limitations: Computationally intensive, often requiring hardware acceleration or approximations for real-time applications. Boosting signals in seismic data
1024-530: Is concentrated about it. Yet another approach is the automatic noise limiter and noise blanker commonly found on HAM radio transceivers, CB radio transceivers, etc. Both of the aforementioned filters can be used separately, or in conjunction with each other at the same time, depending on the transceiver itself. Most digital audio workstations (DAWs) and audio editing software have one or more noise reduction functions. Images taken with digital cameras or conventional film cameras will pick up noise from
1088-400: Is especially crucial for seismic imaging , inversion, and interpretation, thereby greatly improving the success rate in oil & gas exploration. The useful signal that is smeared in the ambient random noise is often neglected and thus may cause fake discontinuity of seismic events and artifacts in the final migrated image. Enhancing the useful signal while preserving edge properties of
1152-592: Is frequently confused with the far more common Dolby noise-reduction system . Unlike Dolby and dbx Type I and Type II noise reduction systems, DNL and DNR are playback-only signal processing systems that do not require the source material to first be encoded. They can be used to remove background noise from any audio signal, including magnetic tape recordings and FM radio broadcasts, reducing noise by as much as 10 dB. They can also be used in conjunction with other noise reduction systems, provided that they are used prior to applying DNR to prevent DNR from causing
1216-408: Is privately held can buy out the shareholders of a public company, taking the company off the public markets. That is typically done through a leveraged buyout and occurs when the buyers believe the securities have been undervalued by investors. In some cases, public companies that are in severe financial distress may also approach a private company or companies to take over ownership and management of
1280-454: Is the ability of a circuit to isolate an undesired signal component from the desired signal component, as with common-mode rejection ratio . All signal processing devices, both analog and digital , have traits that make them susceptible to noise. Noise can be random with an even frequency distribution ( white noise ), or frequency-dependent noise introduced by a device's mechanism or signal processing algorithms . In electronic systems ,
1344-424: Is to define a dynamic threshold for filtering noise, that is derived from the local signal, again with respect to a local time-frequency region. Everything below the threshold will be filtered, everything above the threshold, like partials of a voice or wanted noise , will be untouched. The region is typically defined by the location of the signal's instantaneous frequency, as most of the signal energy to be preserved
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#17327656309731408-653: Is unpredictable or non-stationary. In adaptive filtering, the filter's parameters are continuously adjusted to minimize the difference between the desired signal and the actual output. The Least Mean Squares (LMS) and Recursive Least Squares (RLS) algorithms are commonly used for adaptive noise cancellation. Applications: Used in active noise-canceling headphones, biomedical devices (e.g., EEG and ECG processing), and communications. Advantages: Can adapt to changing noise environments in real-time. Limitations: Higher computational requirements, which may be challenging for real-time applications on low-power devices. Wiener filtering
1472-525: Is used as the audio codec for the ATSC standards , though it was standardized as A/52 by the ATSC. It allows the transport of up to five channels of sound with a sixth channel for low-frequency effects (the so-called "5.1" configuration). In contrast, Japanese ISDB HDTV broadcasts use MPEG's Advanced Audio Coding (AAC) as the audio codec, which also allows 5.1 audio output. DVB allows both. MPEG-2 audio
1536-404: Is when a company has little or no trading activity and the market price is simply the price at which the most recent trade took place, which could be days or weeks ago. This occurs when there are no buyers willing to purchase the securities at the price being offered by the sellers and there are no sellers willing to sell at the price the buyers are willing to pay. While this is rare when the company
1600-739: The DVD specification. Dolby Digital is now found in the HDTV (ATSC) standard of the United States , DVD players , and many satellite-TV and cable-TV receivers. Dolby developed a digital surround sound compression scheme for the TV series The Simpsons . On February 17, 2005, the company became public , offering its shares on the New York Stock Exchange , under the symbol DLB. On March 15, 2005, Dolby celebrated its 40th anniversary at
1664-625: The ShoWest 2005 Festival in San Francisco . On January 8, 2007, Dolby announced the arrival of Dolby Volume at the International Consumer Electronics Show . On June 18, 2010, Dolby introduced Dolby Surround 7.1 , and set up theaters worldwide with 7.1 surround speaker setups to deliver theatrical 7.1 surround sound . The first film to be released with this format was Pixar 's Toy Story 3 which
1728-561: The Hungarian/East-German Ex-Ko system. In some compander systems, the compression is applied during professional media production and only the expansion is applied by the listener; for example, systems like dbx disc , High-Com II , CX 20 and UC used for vinyl recordings and Dolby FM , High Com FM and FMX used in FM radio broadcasting. The first widely used audio noise reduction technique
1792-466: The MPEG-2 system was rejected. Dolby also offered an incentive for Zenith to switch their vote (which they did); however, it is unknown whether they accepted the offer. Audio noise reduction Noise reduction is the process of removing noise from a signal . Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection
1856-511: The United States, companies with over 500 shareholders in some instances are required to report under the Securities Exchange Act of 1934 ; companies that report under the 1934 Act are generally deemed public companies. A public company possess some advantages over privately held businesses. Many stock exchanges require that publicly traded companies have their accounts regularly audited by outside auditors and then publish
1920-470: The accounts to their shareholders. Besides the cost, that may make useful information available to competitors. Various other annual and quarterly reports are also required by law. In the United States, the Sarbanes–Oxley Act imposes additional requirements. The requirement for audited books is not imposed by the exchange known as OTC Pink. The shares may be maliciously held by outside shareholders and
1984-409: The cinema. Dolby Stereo Digital (now simply called Dolby Digital ) was first featured on the 1992 film Batman Returns . Introduced to the home theater market as Dolby AC-3 with the 1995 laserdisc release of Clear and Present Danger , the format did not become widespread in the consumer market, partly because of extra hardware that was necessary to make use of it, until it was adopted as part of
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2048-582: The company headquarters to the United States ( San Francisco , California) in 1976. The first product Dolby Labs produced was the Dolby 301 unit which incorporated Type A Dolby Noise Reduction, a compander -based noise reduction system. These units were intended for use in professional recording studios. Dolby was persuaded by Henry Kloss of KLH to manufacture a consumer version of his noise reduction. Dolby worked more on companding systems and introduced Type B in 1968. Dolby also sought to improve film sound. As
2112-432: The company. One way of doing so would be to make a rights issue designed to enable the new investor to acquire a supermajority . With a supermajority, the company could then be relisted, or privatized. Alternatively, a publicly traded company may be purchased by one or more other publicly traded companies, with the target company becoming either a subsidiary or joint venture of the purchaser(s), or ceasing to exist as
2176-422: The core of international law disputes with regard to industry and trade. Usually, the securities of a publicly traded company are owned by many investors while the shares of a privately held company are owned by relatively few shareholders. A company with many shareholders is not necessarily a publicly traded company. Conversely, a publicly traded company typically (but not necessarily) has many shareholders. In
2240-418: The corporation's history explains: The first film with Dolby sound was A Clockwork Orange (1971). The company was approached by Stanley Kubrick, who wanted to use Dolby’s noise reduction system to facilitate the film’s extensive mixing. The film went on to use Dolby noise reduction on all pre-mixes and masters, but a conventional optical soundtrack on release prints. Callan (1974) was the first film with
2304-503: The film's sensitivity, more sensitive film having larger-sized grains. In magnetic tape, the larger the grains of the magnetic particles (usually ferric oxide or magnetite ), the more prone the medium is to noise. To compensate for this, larger areas of film or magnetic tape may be used to lower the noise to an acceptable level. Noise reduction algorithms tend to alter signals to a greater or lesser degree. The local signal-and-noise orthogonalization algorithm can be used to avoid changes to
2368-444: The firm's stock. For many years, newly-created companies were privately held but held initial public offering to become publicly traded company or to be acquired by another company if they became larger and more profitable or had promising prospects. More infrequently, some companies such as the investment banking firm Goldman Sachs and the logistics services provider United Parcel Service (UPS) chose to remain privately held for
2432-412: The music industry. In May 2020, Dolby launched a developer platform, Dolby.io , aimed at providing developers self-service access to Dolby technologies through public APIs. It allows any person, organization, small and big, to integrate in their websites, apps, games, etc. features such as media enhancements and transcoding, spatial audio, high-quality video communication and low-latency streaming. Over
2496-425: The number of trades in a given period of time, commonly referred to as the "volume" is important when determining how well a company's market capitalization reflects true fair market value of the company as a whole. The higher the volume, the more the fair market value of the company is likely to be reflected by its market capitalization. Another example of the impact of volume on the accuracy of market capitalization
2560-793: The original founders or owners may lose benefits and control. The principal–agent problem , or the agency problem is a key weakness of public companies. The separation of a company's ownership and control is especially prevalent in such countries as the United Kingdom and the United States. In the United States, the Securities and Exchange Commission requires firms whose stock is traded publicly to report their major shareholders each year. The reports identify all institutional shareholders (primarily firms that own stock in other companies), all company officials who own shares in their firm, and all individuals or institutions owning more than 5% of
2624-428: The original signal. Spectral subtraction is one of the simplest and most widely used noise reduction techniques, especially in speech processing. It works by estimating the power spectrum of the noise during silent periods and subtracting this noise spectrum from the noisy signal. This technique assumes that noise is additive and relatively stationary. While effective, spectral subtraction can introduce "musical noise,"
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2688-645: The other noise reduction system to mistrack. One of DNR's first widespread applications was in the GM Delco car stereo systems in US GM cars introduced in 1984. It was also used in factory car stereos in Jeep vehicles in the 1980s, such as the Cherokee XJ . Today, DNR, DNL, and similar systems are most commonly encountered as a noise reduction system in microphone systems. A second class of algorithms work in
2752-523: The playback of phonograph records to address scratches, pops, and surface non-linearities. Single-ended dynamic range expanders like the Phase Linear Autocorrelator Noise Reduction and Dynamic Range Recovery System (Models 1000 and 4000) can reduce various noise from old recordings. Dual-ended systems (such as Dolby noise-reduction system or dbx ) have a pre-emphasis process applied during recording and then
2816-572: The polity in which they reside. In the United States , for example, a public company is usually a type of corporation though a corporation need not be a public company. In the United Kingdom , it is usually a public limited company (plc). In France , it is a société anonyme (SA). In Germany , it is an Aktiengesellschaft (AG). While the general idea of a public company may be similar, differences are meaningful and are at
2880-497: The price per share. For example, a company with two million shares outstanding and a price per share of US$ 40 has a market capitalization of US$ 80 million. However, a company's market capitalization should not be confused with the fair market value of the company as a whole since the price per share are influenced by other factors such as the volume of shares traded. Low trading volume can cause artificially low prices for securities, due to investors being apprehensive of investing in
2944-399: The recording medium at the time of recording. Single-ended hiss reduction systems (such as DNL or DNR ) work to reduce noise as it occurs, including both before and after the recording process as well as for live broadcast applications. Single-ended surface noise reduction (such as CEDAR and the earlier SAE 5000A, Burwen TNE 7000, and Packburn 101/323/323A/323AA and 325 ) is applied to
3008-446: The same reporting requirements as publicly traded companies. Finally, shares in subsidiaries and joint ventures can be (re)-offered to the public at any time. Firms that are sold in this manner are called spin-outs . Most industrialized jurisdictions have enacted laws and regulations that detail the steps that prospective owners (public or private) must undertake if they wish to take over a publicly traded corporation. That often entails
3072-715: The same year, he invented the Dolby Noise Reduction system , a form of audio signal processing for reducing the background hissing sound on cassette tape recordings. His first U.S. patent on the technology was filed in 1969, four years later. The method was first used by Decca Records in the UK. After this, other companies began purchasing Dolby’s A301 technology, which was the professional noise reduction system used in recording, motion picture, broadcasting stations and communications networks. These companies include BBC , Pye , IBC, CBS Studios, RCA, and Granada. He moved
3136-642: The seismic profiles by attenuating random noise can help reduce interpretation difficulties and misleading risks for oil and gas detection. Tape hiss is a performance-limiting issue in analog tape recording . This is related to the particle size and texture used in the magnetic emulsion that is sprayed on the recording media, and also to the relative tape velocity across the tape heads . Four types of noise reduction exist: single-ended pre-recording, single-ended hiss reduction, single-ended surface noise reduction, and codec or dual-ended systems. Single-ended pre-recording systems (such as Dolby HX Pro ), work to affect
3200-438: The signal and noise statistics, which may not always be feasible in real-world applications. Kalman filtering is a recursive algorithm that estimates the state of a dynamic system from a series of noisy measurements. While typically used for tracking and prediction, it is also applicable to noise reduction, especially for signals that can be modeled as time-varying. Kalman filtering is particularly effective in applications where
3264-666: The signal into different frequency components using a wavelet transform and then removes the noise by thresholding the wavelet coefficients. This method is effective for signals with sharp transients, like biomedical signals, because wavelet transforms can provide both time and frequency information. Applications: Commonly used in image processing, ECG and EEG signal denoising, and audio processing. Advantages: Preserves sharp signal features and offers flexibility in handling non-stationary noise. Limitations: The choice of wavelet basis and thresholding parameters significantly impacts performance, requiring careful tuning. Non-local means (NLM)
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#17327656309733328-427: The signal is dynamic and the noise characteristics vary over time. Applications: Used in speech enhancement, radar, and control systems. Advantages: Provides excellent performance for time-varying signals with non-stationary noise. Limitations: Requires a mathematical model of the system dynamics, which may be complex to design for certain applications. Wavelet -based denoising (or wavelet thresholding) decomposes
3392-455: The signal-to-noise ratio on tape up to 10 dB depending on the initial signal volume. When it was played back, the decoder reversed the process, in effect reducing the noise level by up to 10 dB. The Dolby B system (developed in conjunction with Henry Kloss ) was a single-band system designed for consumer products. The Dolby B system, while not as effective as Dolby A, had the advantage of remaining listenable on playback systems without
3456-486: The signals. Noise reduction techniques in Digital Signal Processing (DSP) are essential for improving the quality of signals in various applications, including audio processing, telecommunications, and biomedical engineering. Noise, which is unwanted random variation in signals, can degrade signal clarity and accuracy. DSP offers a range of algorithms to reduce noise while preserving the integrity of
3520-438: The tape at saturation level, audio-style noise reduction is unnecessary. Dynamic noise limiter ( DNL ) is an audio noise reduction system originally introduced by Philips in 1971 for use on cassette decks . Its circuitry is also based on a single chip . It was further developed into dynamic noise reduction ( DNR ) by National Semiconductor to reduce noise levels on long-distance telephony . First sold in 1981, DNR
3584-415: The time-frequency domain using some linear or nonlinear filters that have local characteristics and are often called time-frequency filters . Noise can therefore be also removed by use of spectral editing tools, which work in this time-frequency domain, allowing local modifications without affecting nearby signal energy. This can be done manually much like in a paint program drawing pictures. Another way
3648-428: The turn of the 21st century". Davis argues that technological changes such as the decline in price and increasing power, quality and flexibility of computer numerical control machines and newer digitally enabled tools such as 3D printing will lead to smaller and more local organization of production. In corporate privatization, more often called " going private ," a group of private investors or another company that
3712-409: The would-be buyer(s) making a formal offer for each share of the company to shareholders. The shares of a publicly traded company are often traded on a stock exchange . The value or "size" of a company is called its market capitalization , a term which is often shortened to "market cap". This is calculated as the number of shares outstanding (as opposed to authorized but not necessarily issued) times
3776-494: The years Dolby has introduced several surround sound systems. Their differences are explained below. Matrix decoding can derive Cs (mono surround) or Lrs, Rrs (stereo surrounds) from the Ls and Rs signals L, R, C, LFE, Lss, Rss (side surrounds), Lrs, Rrs (rear surrounds), Lts, Rts (top surrounds). Note: the number and intended location of _output_ channels is defined at playback based on the available loudspeakers. Dolby Digital AC-3
3840-413: Was Game of Thrones . On February 24, 2014, Dolby acquired Doremi Labs for $ 92.5 million in cash plus an additional $ 20 million in contingent consideration that may be earned over a four-year period. In May 2015, Dolby reopened Vine Theatre as a 70-seat showcase theater, known as Dolby @ Vine or Dolby Screening Room Hollywood Vine. In May 2019, Dolby added Dolby Atmos to hundreds of newer songs in
3904-401: Was a contender for the ATSC standard during the " Grand Alliance " shootout, but lost out to Dolby AC-3 . The Grand Alliance issued a statement finding the MPEG-2 system to be "essentially equivalent" to Dolby, but only after the Dolby selection had been made. Later, a story emerged that MIT had entered into an agreement with Dolby whereupon the university would be awarded a large sum of money if
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#17327656309733968-410: Was developed by Ray Dolby in 1966. Intended for professional use, Dolby Type A was an encode/decode system in which the amplitude of frequencies in four bands was increased during recording (encoding), then decreased proportionately during playback (decoding). In particular, when recording quiet parts of an audio signal, the frequencies above 1 kHz would be boosted. This had the effect of increasing
4032-442: Was encoded on the movie A Star Is Born in 1976. In less than ten years, 6,000 cinemas worldwide were equipped to use Dolby Stereo sound. Dolby reworked the system slightly for home use and introduced Dolby Surround , which only extracted a surround channel, and the more impressive Dolby Pro Logic , which was the domestic equivalent of the theatrical Dolby Stereo. Dolby developed a digital surround sound compression scheme for
4096-537: Was later followed by fifty releases using the format. About 80% of films released are now mixed in Dolby Surround 7.1 by default. In April 2012, Dolby introduced its Dolby Atmos , a new cinematic technology adding overhead sound, first applied in Pixar's motion picture Brave . In July 2014, Dolby Laboratories announced plans to bring Atmos to home theater. The first television show to use the technology on disc
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