The Panasonic Lumix DMC-G5 is a digital mirrorless interchangeable lens camera that adheres to the joint Olympus and Panasonic Micro Four Thirds System (MFT system) design standard. It is identified as the twelfth Panasonic MFT camera introduced under the standard and the nineteenth model MFT camera introduced by either Olympus or Panasonic.
81-612: The G5 includes HD video recording capability in AVCHD format. The G5 is the successor to the Panasonic Lumix DMC-G3 and is Panasonic's most junior MFT camera. The G5 differs from the G3 principally by offering a higher maximum ISO (12,800 vs 6,400), a continuous shooting frame rate (6 vs 4 fps), a higher resolution screen, and a new image sensor and processor. Physically, the G5 is very similar to
162-416: A letterbox view of the image, again with correct proportions. The EU defines HD resolution as 1920 x 1080 pixels or 2 073 600 pixels and UHD resolution as 3840 x 2160 pixels or 8 294 400 pixels. Note: Image is either a frame or, in case of interlaced scanning, two fields (EVEN and ODD). Also, there are less common but still popular UltraWide resolutions, such as 2560×1080p (1080p UltraWide). There
243-464: A space-time complexity trade-off between the bytes needed to store or transmit information, and the Computational resources needed to perform the encoding and decoding. The design of data compression schemes involves balancing the degree of compression, the amount of distortion introduced (when using lossy data compression ), and the computational resources or time required to compress and decompress
324-460: A 6 MHz broadcast channel were mostly unsuccessful. All attempts at using this format for terrestrial TV transmission were abandoned by the mid-1990s. Europe developed HD-MAC (1,250 lines, 50 Hz), a member of the MAC family of hybrid analogue/digital video standards; however, it never took off as a terrestrial video transmission format. HD-MAC was never designated for video interchange except by
405-483: A Swiss conference in 1983. The NHK system was standardized in the United States as Society of Motion Picture and Television Engineers (SMPTE) standard #240M in the early 1990s, but abandoned later on when it was replaced by a DVB analog standard. HighVision video is still usable for HDTV video interchange, but there is almost no modern equipment available to perform this function. Attempts at implementing HighVision as
486-444: A decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission , it is called source coding: encoding is done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding , for error detection and correction or line coding , the means for mapping data onto a signal. Data Compression algorithms present
567-494: A form of LPC called adaptive predictive coding (APC), a perceptual coding algorithm that exploited the masking properties of the human ear, followed in the early 1980s with the code-excited linear prediction (CELP) algorithm which achieved a significant compression ratio for its time. Perceptual coding is used by modern audio compression formats such as MP3 and AAC . Discrete cosine transform (DCT), developed by Nasir Ahmed , T. Natarajan and K. R. Rao in 1974, provided
648-415: A further refinement of the direct use of probabilistic modelling , statistical estimates can be coupled to an algorithm called arithmetic coding . Arithmetic coding is a more modern coding technique that uses the mathematical calculations of a finite-state machine to produce a string of encoded bits from a series of input data symbols. It can achieve superior compression compared to other techniques such as
729-460: A higher resolution format, but removing the interlace to match the common 720p format may distort the picture or require filtering which actually reduces the resolution of the final output. Non-cinematic HDTV video recordings are recorded in either the 720p or the 1080i format. The format used is set by the broadcaster (if for television broadcast). In general, 720p is more accurate with fast action, because it progressively scans frames, instead of
810-594: A lossily compressed file for some purpose usually produces a final result inferior to the creation of the same compressed file from an uncompressed original. In addition to sound editing or mixing, lossless audio compression is often used for archival storage, or as master copies. Lossy audio compression is used in a wide range of applications. In addition to standalone audio-only applications of file playback in MP3 players or computers, digitally compressed audio streams are used in most video DVDs, digital television, streaming media on
891-400: A lossy format and a lossless correction; this allows stripping the correction to easily obtain a lossy file. Such formats include MPEG-4 SLS (Scalable to Lossless), WavPack , and OptimFROG DualStream . When audio files are to be processed, either by further compression or for editing , it is desirable to work from an unchanged original (uncompressed or losslessly compressed). Processing of
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#1732863228645972-490: A medium has inherent limitations, such as difficulty of viewing footage while recording, and suffers other problems, caused by poor film development/processing, or poor monitoring systems. Given that there is increasing use of computer-generated or computer-altered imagery in movies, and that editing picture sequences is often done digitally, some directors have shot their movies using the HD format via high-end digital video cameras. While
1053-455: A process known as IMAX HD . Depending upon available bandwidth and the amount of detail and movement in the image, the optimum format for video transfer is either 720p24 or 1080p24. When shown on television in PAL system countries, film must be projected at the rate of 25 frames per second by accelerating it by 4.1 percent. In NTSC standard countries, the projection rate is 30 frames per second, using
1134-402: A representation of digital data that can be decoded to an exact digital duplicate of the original. Compression ratios are around 50–60% of the original size, which is similar to those for generic lossless data compression. Lossless codecs use curve fitting or linear prediction as a basis for estimating the signal. Parameters describing the estimation and the difference between the estimation and
1215-499: A resolution. For example, 24p means 24 progressive scan frames per second and 50i means 25 progressive frames per second, consisting of 50 interlaced fields per second. Most HDTV systems support some standard resolutions and frame or field rates. The most common are noted below. High-definition signals require a high-definition television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (1.78:1). The aspect ratio of regular widescreen film shot today
1296-582: A result, speech can be encoded at high quality using a relatively low bit rate. This is accomplished, in general, by some combination of two approaches: The earliest algorithms used in speech encoding (and audio data compression in general) were the A-law algorithm and the μ-law algorithm . Early audio research was conducted at Bell Labs . There, in 1950, C. Chapin Cutler filed the patent on differential pulse-code modulation (DPCM). In 1973, Adaptive DPCM (ADPCM)
1377-418: A special case of data differencing . Data differencing consists of producing a difference given a source and a target, with patching reproducing the target given a source and a difference. Since there is no separate source and target in data compression, one can consider data compression as data differencing with empty source data, the compressed file corresponding to a difference from nothing. This
1458-440: A technique called 3:2 pull-down. One film frame is held for three video fields (1/20 of a second), and the next is held for two video fields (1/30 of a second) and then the process is repeated, thus achieving the correct film projection rate with two film frames shown in one twelfth of a second. Older (pre-HDTV) recordings on video tape such as Betacam SP are often either in the form 480i60 or 576i50. These may be upconverted to
1539-583: A technique which is often known as filmizing . The first electronic scanning format, 405 lines , was the first high definition television system, since the mechanical systems it replaced had far fewer. From 1939, Europe and the US tried 605 and 441 lines until, in 1941, the FCC mandated 525 for the US. In wartime France, René Barthélemy tested higher resolutions, up to 1,042. In late 1949, official French transmissions finally began with 819 . In 1984, however, this standard
1620-772: A zip file's compressed size includes both the zip file and the unzipping software, since you can not unzip it without both, but there may be an even smaller combined form. Examples of AI-powered audio/video compression software include NVIDIA Maxine , AIVC. Examples of software that can perform AI-powered image compression include OpenCV , TensorFlow , MATLAB 's Image Processing Toolbox (IPT) and High-Fidelity Generative Image Compression. In unsupervised machine learning , k-means clustering can be utilized to compress data by grouping similar data points into clusters. This technique simplifies handling extensive datasets that lack predefined labels and finds widespread use in fields such as image compression . Data compression aims to reduce
1701-594: Is acute for surveillance purposes to ensure that the quality of the video output is of an acceptable standard that can be used both for preventative surveillance as well as for evidence purposes. Although, HD cameras can be highly effective indoor, special industries with outdoor environments called for a need to produce much higher resolutions for effective coverage. The ever-evolving image sensor technologies allowed manufacturers to develop cameras with 10-20 MP resolutions, which therefore have become efficient instruments to monitor larger areas. In order to further increase
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#17328632286451782-637: Is also a WQHD+ option for some of these. High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, high definition disc ( BD ), digital cameras, Internet downloads, and video game consoles. Blu-ray Discs were jointly developed by 9 initial partners including Sony and Phillips (which jointly developed CDs for audio), and Pioneer (which developed its own Laser-disc previously with some success) among others. HD DVD discs were primarily developed by Toshiba and NEC with some backing from Microsoft, Warner Bros., Hewlett Packard, and others. On February 19, 2008, Toshiba announced it
1863-598: Is an unusual case, due to its hybrid nature as both a home console and a handheld: the built-in screen displays games at 720p maximum, but the console can natively display imagery at 1080p when docked. The Xbox One X and PlayStation 4 Pro can display some games in 4K. The PlayStation 5 and Xbox Series X can display games in 4K and 8K. Generally, PC games are only limited by the display's resolution and GPU driver support. Some PC hardware supports DisplayPort 2.1 for native 8k resolution at high refresh rates. Ultrawide monitors are supported, which can display more of
1944-428: Is considered high-definition. 480 scan lines is generally the minimum even though the majority of systems greatly exceed that. Images of standard resolution captured at rates faster than normal (60 frames/second North America, 50 fps Europe), by a high-speed camera may be considered high-definition in some contexts. Some television series shot on high-definition video are made to look as if they have been shot on film ,
2025-650: Is distinguished as a separate discipline from general-purpose audio compression. Speech coding is used in internet telephony , for example, audio compression is used for CD ripping and is decoded by the audio players. Lossy compression can cause generation loss . The theoretical basis for compression is provided by information theory and, more specifically, Shannon's source coding theorem ; domain-specific theories include algorithmic information theory for lossless compression and rate–distortion theory for lossy compression. These areas of study were essentially created by Claude Shannon , who published fundamental papers on
2106-408: Is either lossy or lossless . Lossless compression reduces bits by identifying and eliminating statistical redundancy . No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as
2187-411: Is on the order of 23 ms. Speech encoding is an important category of audio data compression. The perceptual models used to estimate what aspects of speech a human ear can hear are generally somewhat different from those used for music. The range of frequencies needed to convey the sounds of a human voice is normally far narrower than that needed for music, and the sound is normally less complex. As
2268-420: Is perceptually irrelevant, most lossy compression algorithms use transforms such as the modified discrete cosine transform (MDCT) to convert time domain sampled waveforms into a transform domain, typically the frequency domain . Once transformed, component frequencies can be prioritized according to how audible they are. Audibility of spectral components is assessed using the absolute threshold of hearing and
2349-426: Is processed. In the minimum case, latency is zero samples (e.g., if the coder/decoder simply reduces the number of bits used to quantize the signal). Time domain algorithms such as LPC also often have low latencies, hence their popularity in speech coding for telephony. In algorithms such as MP3, however, a large number of samples have to be analyzed to implement a psychoacoustic model in the frequency domain, and latency
2430-429: Is reduced, using methods such as coding , quantization , DCT and linear prediction to reduce the amount of information used to represent the uncompressed data. Lossy audio compression algorithms provide higher compression and are used in numerous audio applications including Vorbis and MP3 . These algorithms almost all rely on psychoacoustics to eliminate or reduce fidelity of less audible sounds, thereby reducing
2511-402: Is the same as considering absolute entropy (corresponding to data compression) as a special case of relative entropy (corresponding to data differencing) with no initial data. The term differential compression is used to emphasize the data differencing connection. Entropy coding originated in the 1940s with the introduction of Shannon–Fano coding , the basis for Huffman coding which
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2592-425: Is typically 1.85:1 or 2.39:1 (sometimes traditionally quoted at 2.35:1). Standard-definition television (SDTV) has a 4:3 (1.33:1) aspect ratio, although in recent years many broadcasters have transmitted programs squeezed horizontally in 16:9 anamorphic format , in hopes that the viewer has a 16:9 set which stretches the image out to normal-looking proportions, or a set which squishes the image vertically to present
2673-435: Is used in digital cameras , to increase storage capacities. Similarly, DVDs , Blu-ray and streaming video use lossy video coding formats . Lossy compression is extensively used in video. In lossy audio compression, methods of psychoacoustics are used to remove non-audible (or less audible) components of the audio signal . Compression of human speech is often performed with even more specialized techniques; speech coding
2754-668: Is used in the GIF format, introduced in 1987. DEFLATE , a lossless compression algorithm specified in 1996, is used in the Portable Network Graphics (PNG) format. Wavelet compression , the use of wavelets in image compression, began after the development of DCT coding. The JPEG 2000 standard was introduced in 2000. In contrast to the DCT algorithm used by the original JPEG format, JPEG 2000 instead uses discrete wavelet transform (DWT) algorithms. JPEG 2000 technology, which includes
2835-608: The Advanced Television Systems Committee (ATSC) adopted a range of standards from interlaced 1,080-line video (a technical descendant of the original analog NHK 1125/30 Hz system) with a maximum frame rate of 30 Hz, (60 fields per second) and 720-line video, progressively scanned, with a maximum frame rate of 60 Hz. In the end, however, the DVB standard of resolutions (1080, 720, 480) and respective frame rates (24, 25, 30) were adopted in conjunction with
2916-514: The European Broadcasting Union . High-definition digital video was not possible with uncompressed video due to impractically high memory and bandwidth requirements, with a bit rate exceeding 1 Gbit/s for 1080p video. Digital HDTV was enabled by the development of discrete cosine transform (DCT) video compression . The DCT is a lossy compression technique that was first proposed by Nasir Ahmed in 1972, and
2997-625: The Internet , satellite and cable radio, and increasingly in terrestrial radio broadcasts. Lossy compression typically achieves far greater compression than lossless compression, by discarding less-critical data based on psychoacoustic optimizations. Psychoacoustics recognizes that not all data in an audio stream can be perceived by the human auditory system . Most lossy compression reduces redundancy by first identifying perceptually irrelevant sounds, that is, sounds that are very hard to hear. Typical examples include high frequencies or sounds that occur at
3078-462: The Lempel–Ziv–Welch (LZW) algorithm rapidly became the method of choice for most general-purpose compression systems. LZW is used in GIF images, programs such as PKZIP , and hardware devices such as modems. LZ methods use a table-based compression model where table entries are substituted for repeated strings of data. For most LZ methods, this table is generated dynamically from earlier data in
3159-501: The Motion JPEG 2000 extension, was selected as the video coding standard for digital cinema in 2004. Audio data compression, not to be confused with dynamic range compression , has the potential to reduce the transmission bandwidth and storage requirements of audio data. Audio compression formats compression algorithms are implemented in software as audio codecs . In both lossy and lossless compression, information redundancy
3240-580: The Panasonic Lumix DMC-G3 , but it has a larger hand grip. However, most of the camera's functionality is also accessible through the touch-control LCD panel. No Video | Weather Sealed | All the Rest HD video High-definition video ( HD video ) is video of higher resolution and quality than standard-definition . While there is no standardized meaning for high-definition , generally any video image with considerably more than 480 vertical scan lines (North America) or 576 vertical lines (Europe)
3321-634: The PlayStation 3 the Xbox 360 game consoles can output native 1080p through HDMI or component cables, but the systems have few games which appear in 1080p; most games only run natively at 720p or less but can be upscaled to 1080p. Visually, native 1080p produces a sharper and clearer picture compared to upscaled 1080p. The Wii does not support HD. In the 8th generation , Nintendo's Wii U and Nintendo Switch , Microsoft's Xbox One , and Sony's PlayStation 4 display games 1080p natively. The Nintendo Switch
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3402-470: The University of Buenos Aires . In 1983, using the psychoacoustic principle of the masking of critical bands first published in 1967, he started developing a practical application based on the recently developed IBM PC computer, and the broadcast automation system was launched in 1987 under the name Audicom . 35 years later, almost all the radio stations in the world were using this technology manufactured by
3483-500: The discrete cosine transform (DCT). It was first proposed in 1972 by Nasir Ahmed , who then developed a working algorithm with T. Natarajan and K. R. Rao in 1973, before introducing it in January 1974. DCT is the most widely used lossy compression method, and is used in multimedia formats for images (such as JPEG and HEIF ), video (such as MPEG , AVC and HEVC) and audio (such as MP3 , AAC and Vorbis ). Lossy image compression
3564-506: The linear predictive coding (LPC) used with speech, are source-based coders. LPC uses a model of the human vocal tract to analyze speech sounds and infer the parameters used by the model to produce them moment to moment. These changing parameters are transmitted or stored and used to drive another model in the decoder which reproduces the sound. Lossy formats are often used for the distribution of streaming audio or interactive communication (such as in cell phone networks). In such applications,
3645-606: The probability distribution of the input data. An early example of the use of arithmetic coding was in an optional (but not widely used) feature of the JPEG image coding standard. It has since been applied in various other designs including H.263 , H.264/MPEG-4 AVC and HEVC for video coding. Archive software typically has the ability to adjust the "dictionary size", where a larger size demands more random-access memory during compression and decompression, but compresses stronger, especially on repeating patterns in files' content. In
3726-420: The 1080i, which uses interlaced fields and thus might degrade the resolution of fast images. 720p is used more for Internet distribution of high-definition video, because computer monitors progressively scan; 720p video has lower storage-decoding requirements than either the 1080i or the 1080p. This is also the medium for high-definition broadcasts around the world and 1080p is used for Blu-ray movies. Film as
3807-516: The Europeans that were also involved in the same standardization process. The FCC officially adopted the ATSC transmission standard in 1996 (which included both HD and SD video standards). In the early 2000s, it looked as if DVB would be the video standard far into the future. However, both Brazil and China have adopted alternative standards for high-definition video that preclude the interoperability that
3888-516: The Techniscope 2 perforation format. Movies are also produced using other film gauges , including 70 mm films (22 mm × 48 mm) or the rarely used 55 mm and CINERAMA . The four major film formats provide pixel resolutions (calculated from pixels per millimeter) roughly as follows: In the process of making prints for exhibition, this negative is copied onto other film (negative → interpositive → internegative → print) causing
3969-506: The actual signal are coded separately. A number of lossless audio compression formats exist. See list of lossless codecs for a listing. Some formats are associated with a distinct system, such as Direct Stream Transfer , used in Super Audio CD and Meridian Lossless Packing , used in DVD-Audio , Dolby TrueHD , Blu-ray and HD DVD . Some audio file formats feature a combination of
4050-403: The amount of data required to represent an image at the cost of a relatively small reduction in image quality and has become the most widely used image file format . Its highly efficient DCT-based compression algorithm was largely responsible for the wide proliferation of digital images and digital photos . Lempel–Ziv–Welch (LZW) is a lossless compression algorithm developed in 1984. It
4131-418: The basis for the modified discrete cosine transform (MDCT) used by modern audio compression formats such as MP3, Dolby Digital , and AAC. MDCT was proposed by J. P. Princen, A. W. Johnson and A. B. Bradley in 1987, following earlier work by Princen and Bradley in 1986. The world's first commercial broadcast automation audio compression system was developed by Oscar Bonello, an engineering professor at
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#17328632286454212-487: The better-known Huffman algorithm. It uses an internal memory state to avoid the need to perform a one-to-one mapping of individual input symbols to distinct representations that use an integer number of bits, and it clears out the internal memory only after encoding the entire string of data symbols. Arithmetic coding applies especially well to adaptive data compression tasks where the statistics vary and are context-dependent, as it can be easily coupled with an adaptive model of
4293-410: The coding algorithm can be critical; for example, when there is a two-way transmission of data, such as with a telephone conversation, significant delays may seriously degrade the perceived quality. In contrast to the speed of compression, which is proportional to the number of operations required by the algorithm, here latency refers to the number of samples that must be analyzed before a block of audio
4374-654: The core information of the original data while significantly decreasing the required storage space. Large language models (LLMs) are also capable of lossless data compression, as demonstrated by DeepMind 's research with the Chinchilla 70B model. Developed by DeepMind, Chinchilla 70B effectively compressed data, outperforming conventional methods such as Portable Network Graphics (PNG) for images and Free Lossless Audio Codec (FLAC) for audio. It achieved compression of image and audio data to 43.4% and 16.4% of their original sizes, respectively. Data compression can be viewed as
4455-467: The data in question. For example, the human eye is more sensitive to subtle variations in luminance than it is to the variations in color. JPEG image compression works in part by rounding off nonessential bits of information. A number of popular compression formats exploit these perceptual differences, including psychoacoustics for sound, and psychovisuals for images and video. Most forms of lossy compression are based on transform coding , especially
4536-439: The data may be encoded as "279 red pixels". This is a basic example of run-length encoding ; there are many schemes to reduce file size by eliminating redundancy. The Lempel–Ziv (LZ) compression methods are among the most popular algorithms for lossless storage. DEFLATE is a variation on LZ optimized for decompression speed and compression ratio, but compression can be slow. In the mid-1980s, following work by Terry Welch ,
4617-462: The data must be decompressed as the data flows, rather than after the entire data stream has been transmitted. Not all audio codecs can be used for streaming applications. Latency is introduced by the methods used to encode and decode the data. Some codecs will analyze a longer segment, called a frame , of the data to optimize efficiency, and then code it in a manner that requires a larger segment of data at one time to decode. The inherent latency of
4698-408: The data. Lossless data compression algorithms usually exploit statistical redundancy to represent data without losing any information , so that the process is reversible. Lossless compression is possible because most real-world data exhibits statistical redundancy. For example, an image may have areas of color that do not change over several pixels; instead of coding "red pixel, red pixel, ..."
4779-623: The early 1990s, DCT video compression had been widely adopted as the video coding standard for HDTV. The current high-definition video standards in North America were developed during the course of the advanced television process initiated by the Federal Communications Commission in 1987 at the request of American broadcasters. In essence, the end of the 1980s was a death knell for most analog high definition technologies that had developed up to that time. The FCC process, led by
4860-577: The ease of transfer to editing systems for special effects. Depending on the year and format in which a movie was filmed, the exposed image can vary greatly in size. Sizes range from as big as 24 mm × 36 mm for VistaVision / Technirama 8 perforation cameras (same as 35 mm still photo film) going down through 18 mm × 24 mm for Silent Films or Full Frame 4 perforations cameras to as small as 9 mm × 21 mm in Academy Sound Aperture cameras modified for
4941-469: The file size is reduced to 5-20% of the original size and a megabyte can store about a minute's worth of music at adequate quality. Several proprietary lossy compression algorithms have been developed that provide higher quality audio performance by using a combination of lossless and lossy algorithms with adaptive bit rates and lower compression ratios. Examples include aptX , LDAC , LHDC , MQA and SCL6 . To determine what information in an audio signal
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#17328632286455022-443: The game world than a traditional display with a 16:9 aspect ratio , and multi-monitor setups are possible, such as having a single game span across three monitors for a more immersive experience. Video compression In information theory , data compression , source coding , or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression
5103-436: The image detail produced by these formats can be far below that of broadcast HD, and often even inferior to DVD-Video (3-9 Mbit/s MP2) upscaled to the same image size. The following is a chart of numerous online services and their HD offering: Since the late 2000s a considerably large number of security camera manufacturers have started to produce HD cameras. The need for high resolution, color fidelity, and frame rate
5184-693: The input. The table itself is often Huffman encoded . Grammar-based codes like this can compress highly repetitive input extremely effectively, for instance, a biological data collection of the same or closely related species, a huge versioned document collection, internet archival, etc. The basic task of grammar-based codes is constructing a context-free grammar deriving a single string. Other practical grammar compression algorithms include Sequitur and Re-Pair . The strongest modern lossless compressors use probabilistic models, such as prediction by partial matching . The Burrows–Wheeler transform can also be viewed as an indirect form of statistical modelling. In
5265-455: The late 1980s, digital images became more common, and standards for lossless image compression emerged. In the early 1990s, lossy compression methods began to be widely used. In these schemes, some loss of information is accepted as dropping nonessential detail can save storage space. There is a corresponding trade-off between preserving information and reducing size. Lossy data compression schemes are designed by research on how people perceive
5346-473: The principles of simultaneous masking —the phenomenon wherein a signal is masked by another signal separated by frequency—and, in some cases, temporal masking —where a signal is masked by another signal separated by time. Equal-loudness contours may also be used to weigh the perceptual importance of components. Models of the human ear-brain combination incorporating such effects are often called psychoacoustic models . Other types of lossy compressors, such as
5427-457: The quality of HD video is very high compared to SD video, and offers improved signal/noise ratios against comparable sensitivity film, film remains able to resolve more image detail than current HD video formats. In addition some films have a wider dynamic range (ability to resolve extremes of dark and light areas in a scene) than even the best HD cameras. Thus the most persuasive arguments for the use of HD are currently cost savings on film stock and
5508-437: The resolution of security cameras, some manufacturers developed multi-sensor cameras. Within these devices several sensor-lens combinations produce the images, which are later merged during image processing . These security cameras are able to deliver even hundreds of megapixels with motion picture frame rate. Such high resolutions, however, requires special recording, storage and also video stream display technologies. Both
5589-437: The resolution to be reduced with each emulsion copying step and when the image passes through a lens (for example, on a projector). In many cases, the resolution can be reduced down to 1/6 of the original negative's resolution (or worse). Note that resolution values for 70 mm film are higher than those listed above. Many online video streaming, on-demand and digital download services offer HD video. Due to heavy compression,
5670-488: The same time as louder sounds. Those irrelevant sounds are coded with decreased accuracy or not at all. Due to the nature of lossy algorithms, audio quality suffers a digital generation loss when a file is decompressed and recompressed. This makes lossy compression unsuitable for storing the intermediate results in professional audio engineering applications, such as sound editing and multitrack recording. However, lossy formats such as MP3 are very popular with end-users as
5751-546: The size of data files, enhancing storage efficiency and speeding up data transmission. K-means clustering, an unsupervised machine learning algorithm, is employed to partition a dataset into a specified number of clusters, k, each represented by the centroid of its points. This process condenses extensive datasets into a more compact set of representative points. Particularly beneficial in image and signal processing , k-means clustering aids in data reduction by replacing groups of data points with their centroids, thereby preserving
5832-592: The space required to store or transmit them. The acceptable trade-off between loss of audio quality and transmission or storage size depends upon the application. For example, one 640 MB compact disc (CD) holds approximately one hour of uncompressed high fidelity music, less than 2 hours of music compressed losslessly, or 7 hours of music compressed in the MP3 format at a medium bit rate . A digital sound recorder can typically store around 200 hours of clearly intelligible speech in 640 MB. Lossless audio compression produces
5913-511: The symbol that compresses best, given the previous history). This equivalence has been used as a justification for using data compression as a benchmark for "general intelligence". An alternative view can show compression algorithms implicitly map strings into implicit feature space vectors , and compression-based similarity measures compute similarity within these feature spaces. For each compressor C(.) we define an associated vector space ℵ, such that C(.) maps an input string x, corresponding to
5994-478: The topic in the late 1940s and early 1950s. Other topics associated with compression include coding theory and statistical inference . There is a close connection between machine learning and compression. A system that predicts the posterior probabilities of a sequence given its entire history can be used for optimal data compression (by using arithmetic coding on the output distribution). Conversely, an optimal compressor can be used for prediction (by finding
6075-503: The vector norm ||~x||. An exhaustive examination of the feature spaces underlying all compression algorithms is precluded by space; instead, feature vectors chooses to examine three representative lossless compression methods, LZW, LZ77, and PPM. According to AIXI theory, a connection more directly explained in Hutter Prize , the best possible compression of x is the smallest possible software that generates x. For example, in that model,
6156-590: Was abandoned for 625-line color on the TF1 network. Modern HD specifications date to the early 1980s, when Japanese engineers developed the HighVision 1,125-line interlaced TV standard (also called MUSE ) that ran at 60 frames per second. The Sony HDVS system was presented at an international meeting of television engineers in Algiers , April 1981 and Japan's NHK presented its analog high-definition television (HDTV) system at
6237-497: Was abandoning the format and would discontinue development, marketing and manufacturing of HD DVD players and drives. The high resolution photographic film used for cinema projection is exposed at the rate of 24 frames per second but usually projected at 48, each frame getting projected twice helping to minimise flicker. One exception to this was the 1986 National Film Board of Canada short film Momentum , which briefly experimented with both filming and projecting at 48 frame/s, in
6318-591: Was developed in 1950. Transform coding dates back to the late 1960s, with the introduction of fast Fourier transform (FFT) coding in 1968 and the Hadamard transform in 1969. An important image compression technique is the discrete cosine transform (DCT), a technique developed in the early 1970s. DCT is the basis for JPEG, a lossy compression format which was introduced by the Joint Photographic Experts Group (JPEG) in 1992. JPEG greatly reduces
6399-427: Was hoped for after decades of largely non-interoperable analog TV broadcasting. High definition video (prerecorded and broadcast) is defined threefold, by: Often, the rate is inferred from the context, usually assumed to be either 50 Hz (Europe) or 60 Hz (USA), except for 1080p , which denotes 1080p24, 1080p25, and 1080p30, but also 1080p50 and 1080p60. A frame or field rate can also be specified without
6480-425: Was introduced by P. Cummiskey, Nikil S. Jayant and James L. Flanagan . Perceptual coding was first used for speech coding compression, with linear predictive coding (LPC). Initial concepts for LPC date back to the work of Fumitada Itakura ( Nagoya University ) and Shuzo Saito ( Nippon Telegraph and Telephone ) in 1966. During the 1970s, Bishnu S. Atal and Manfred R. Schroeder at Bell Labs developed
6561-546: Was later adapted into a motion-compensated DCT algorithm for video coding formats such as the H.26x formats from the Video Coding Experts Group from 1988 onwards and the MPEG formats from 1993 onwards. Motion-compensated DCT compression significantly reduced the amount of memory and bandwidth required for digital video, capable of achieving a data compression ratio of around 100:1 compared to uncompressed video. By
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