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Digital Imaging
Digital imaging or digital image acquisition is the creation of a representation of the visual characteristics of an object,[1] such as a physical scene or the interior structure of an object. The term is often assumed to imply or include the processing, compression, storage, printing, and display of such images. A key advantage of a digital image, versus an analog image such as a film photograph, is the ability to make copies and copies of copies digitally indefinitely without any loss of image quality. Digital imaging can be classified by the type of electromagnetic radiation or other waves whose variable attenuation, as they pass through or reflect off objects, conveys the information that constitutes the image. In all classes of digital imaging, the information is converted by image sensors into digital signals that are processed by a computer and made output as a visible-light image
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View From The Window At Le Gras
View from the Window at Le Gras[2] is a heliographic image and the oldest surviving camera photograph. It was created by French inventor Nicéphore Niépce in 1827 (assumed 9 February 1826) in Saint-Loup-de-Varennes, France, and shows parts of the buildings and surrounding countryside of his estate, Le Gras, as seen from a high window. Niépce captured the scene with a camera obscura focused onto a 16.2 cm × 20.2 cm (6.4 in × 8.0 in) pewter plate thinly coated with Bitumen of Judea, a naturally occurring asphalt.[3] The bitumen hardened in the brightly lit areas, but in the dimly lit areas it remained soluble and could be washed away with a mixture of oil of lavender and white petroleum.[3] A very long exposure in the camera was required. Sunlight strikes the buildings on opposite sides, suggesting an exposure that lasted about eight hours, which has become the traditional estimate
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Positron Emission Tomography
Positron emission tomography (PET)[1] is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body. For example, 18F-FDG is commonly used to detect cancer, NaF-F18 is widely used for detecting bone formation, and oxygen-15 is sometimes used to measure blood flow. PET is a common imaging technique, a medical scintillography technique used in nuclear medicine. A radiopharmaceutical – a radioisotope attached to a drug is injected into the body as a tracer
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Sound

In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain.[1] Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimetres (0.67 in)
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Radio Wave
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 gigahertz (GHz) to as low as 30 hertz (Hz).[1] At 300 GHz, the corresponding wavelength is 1 mm (shorter than a grain of rice); at 30 Hz the corresponding wavelength is 10,000 km (longer than the radius of the Earth). Like all other electromagnetic waves, radio waves travel at the speed of light in vacuum (and close to the speed of light in the Earth's atmosphere, which acts as the transmission media for the vast majority of terrestrial use). Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents.[2] Naturally occurring radio waves are emitted by lightning and astronomical objects. Radio waves are generated artificially by transmitters and received by radio receivers, using antennas
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Image Analysis
Image analysis is the extraction of meaningful information from images; mainly from digital images by means of digital image processing techniques.[1] Image analysis tasks can be as simple as reading bar coded tags or as sophisticated as identifying a person from their face. Computers are indispensable for the analysis of large amounts of data, for tasks that require complex computation, or for the extraction of quantitative information. On the other hand, the human visual cortex is an excellent image analysis apparatus, especially for extracting higher-level information, and for many applications — including medicine, security, and remote sensing — human analysts still cannot be replaced by computers
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Nicéphore Niépce

Joseph Nicéphore Niépce (French: [nisefɔʁ njɛps]; 7 March 1765 – 5 July 1833),[1] commonly known or referred to simply as Nicéphore Niépce, was a French inventor, usually credited as the inventor of photography and a pioneer in that field.[2] Niépce developed heliography, a technique he used to create the world's oldest surviving product of a photographic process: a print made from a photoengraved printing plate in 1825.[3] In 1826 or 1827, he used a primitive camera to produce the oldest surviving photograph of a real-world scene
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Scintigraphy
Scintigraphy (from Latin scintilla, "spark"), also known as a gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally and the emitted gamma radiation is captured by external detectors (gamma cameras) to form two-dimensional[1] images in a similar process to the capture of x-ray images. In contrast, SPECT and positron emission tomography (PET) form 3-dimensional images, and are therefore classified as separate techniques to scintigraphy, although they also use gamma cameras to detect internal radiation
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