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Full-spectrum Photography
Full-spectrum photography is a subset of multispectral imaging, defined among photography enthusiasts as imaging with consumer cameras the full, broad spectrum of a film or camera sensor bandwidth. In practice, specialized broadband/full-spectrum film captures visible and near infrared light, commonly referred to as the " VNIR". Definition of VNIR. Modified digital cameras can detect some , all of the visible and much of the near infrared spectrum, as most digital imaging sensors are sensitive from about 350 nm to 1000 nm. An off-the-shelf digital camera contains an infrared filter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperspectral Imaging
Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifying materials, or detecting processes. There are three general types of spectral imagers. There are push broom scanners and the related whisk broom scanners (spatial scanning), which read images over time, band sequential scanners (spectral scanning), which acquire images of an area at different wavelengths, and snapshot hyperspectral imagers, which uses a staring array to generate an image in an instant. Whereas the human eye sees color of visible light in mostly three bands (long wavelengths, perceived as red; medium wavelengths, perceived as green; and short wavelengths, perceived as blue), spectral imaging divides the spectrum into many more bands. This technique of dividing images into bands can be extended beyond the visible. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Image Processing
Digital image processing is the use of a digital computer to process digital images through an algorithm. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing. It allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the build-up of Noise (signal processing), noise and distortion during processing. Since images are defined over two dimensions (perhaps more), digital image processing may be modeled in the form of Multidimensional system, multidimensional systems. The generation and development of digital image processing are mainly affected by three factors: first, the development of computers; second, the development of mathematics (especially the creation and improvement of discrete mathematics, discrete mathematics theory); and third, the demand for a wide range of applications in environment, agriculture, military, industry and medical science has incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Path Length
In optics, optical path length (OPL, denoted ''Λ'' in equations), also known as optical length or optical distance, is the length that light needs to travel through a vacuum to create the same phase difference as it would have when traveling through a given medium. It is calculated by taking the product of the geometric length of the optical path followed by light and the refractive index of the homogeneous medium through which the light ray propagates; for inhomogeneous optical media, the product above is generalized as a path integral as part of the ray tracing procedure. A difference in OPL between two paths is often called the optical path difference (OPD). OPL and OPD are important because they determine the phase of the light and govern interference and diffraction of light as it propagates. In a medium of constant refractive index, ''n'', the OPL for a path of geometrical length ''s'' is just :\mathrm = n s .\, If the refractive index varies along the path, the OPL is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Film
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and image resolution, resolution of the film. Film is typically segmented in ''frames'', that give rise to separate photographs. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure (photography), exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which can be chemically photographic processing, developed into a visible photograph. In addition to visible light, all films are sensitive to ultraviolet light, X-rays, gamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Sensor
A digital sensor is an electronic or electrochemical sensor, where data is digitally converted and transmitted. Sensors are often used for analytical measurements, e.g. the measurement of chemical and physical properties of liquids. Examples of measured parameters are pH value, conductivity, oxygen, redox potentials. Such measurements are used in the industrialized world and give vital input for process control. Analog sensors were used in the past, but digital sensors have come to dominate in the age of microprocessors. The differences between the two types, and the reasons for the development of digital sensors are discussed: General aspects Digital sensors are the modern successors of analog sensors. Digital sensors replace analog sensors stepwise, because they overcome the traditional drawbacks of analog sensor systems (cf chapter 3 –which book?) History Electronic and electrochemical sensors are typically one part of a measuring chain. A measuring chain comprises the se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Vis IR Portrait
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. These interacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FinePix IS Pro
The FinePix IS Pro is a digital single lens reflex camera introduced by Fujifilm in 2007. It is based on a FinePix S5 Pro, which is in turn based on the Nikon D200. It has a Nikon F lens mount and can use most lenses made for 35 mm Nikon SLR cameras. It replaces the Fujifilm FinePix S3 Pro UVIR. Unlike most digital cameras, there is no IR or ultraviolet, UV filtering in front of the image sensor. This results in a wide spectral response of approximately 1000 Nanometer, nm to 380 nm (infrared to ultraviolet). Suitable external bandpass filters are required to photograph in IR or UV wavelengths. Infrared filters are readily available at low cost from many sources, but ultraviolet filters – and suitable lenses – can be expensive. Photography in infrared and ultraviolet poses its own special challenges regarding exposure and – above all – focusing a SLR camera. By definition, these forms of light are invisible to the human eye. The IS Pro includes a Live previe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychosis
In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or incoherent thoughts or speech. Psychosis is a description of a person's state or symptoms, rather than a particular mental illness, and it is not related to psychopathy (a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits). Common causes of chronic (i.e. ongoing or repeating) psychosis include schizophrenia or schizoaffective disorder, bipolar disorder, and brain damage (usually as a result of alcoholism). Acute (temporary) psychosis can also be caused by severe distress, sleep deprivation, sensory deprivation, some medications, and drug use (including alcohol, cannabis, hallucinogens, and stimulants). Acute psychosis is termed primary if it results from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Camera
A digital camera, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Digital cameras are now widely incorporated into mobile devices like smartphones with the same or more capabilities and features of dedicated cameras. High-end, high-definition dedicated cameras are still commonly used by professionals and those who desire to take higher-quality photographs. Digital and digital movie cameras share an optical system, typically using a Camera lens, lens with a variable Diaphragm (optics), diaphragm to focus light onto an image pickup device. The diaphragm and Shutter (photography), shutter admit a controlled amount of light to the image, just as with film, but the image pickup device is electronic rather than chemical. However, unlike film cameras, digital cameras can display images on a screen immediately afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forensic Photography
Forensic photography may refer to the visual documentation of different aspects that can be found at a crime scene. It may include the documentation of the crime scene, or physical evidence that is either found at a crime scene or already processed in a laboratory. Forensic photography differs from other variations of photography because crime scene photographers usually have a very specific purpose for capturing each image. As a result, the quality of forensic documentation may determine the result of an investigation; in the absence of good documentation, investigators may find it impossible to conclude what did or did not happen. Crime scenes can be major sources of physical evidence that is used to associate or link suspects to scenes, victims to scenes, and suspects to victims. Locard's exchange principle is a major concept that helps determine these relationships of evidence. It is the basic tenet of why crime scenes should be investigated. Anything found at a crime scen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Thickness
In physics, optical depth or optical thickness is the natural logarithm of the ratio of incident to ''transmitted'' radiant power through a material. Thus, the larger the optical depth, the smaller the amount of transmitted radiant power through the material. Spectral optical depth or spectral optical thickness is the natural logarithm of the ratio of incident to transmitted spectral radiant power through a material. Optical depth is dimensionless, and in particular is not a length, though it is a monotonically increasing function of optical path length, and approaches zero as the path length approaches zero. The use of the term "optical density" for optical depth is discouraged. In chemistry, a closely related quantity called "absorbance" or "decadic absorbance" is used instead of optical depth: the common logarithm of the ratio of incident to transmitted radiant power through a material. It is the optical depth divided by , because of the different logarithm bases used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
