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Contrast (vision)
Contrast is the difference in luminance or color that makes an object (or its representation in an image or display) visible against a background of different luminance or color. The human visual system is more sensitive to contrast than to absolute luminance; thus, we can perceive the world similarly despite significant changes in illumination throughout the day or across different locations. The maximum contrast of an image is termed the contrast ratio or dynamic range. In images where the contrast ratio approaches the maximum possible for the medium, there is a ''conservation of contrast''. In such cases, increasing contrast in certain parts of the image will necessarily result in a decrease in contrast elsewhere. Brightening an image increases contrast in darker areas but decreases it in brighter areas; conversely, darkening the image will have the opposite effect. Bleach bypass reduces contrast in the darkest and brightest parts of an image while enhancing luminance contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Change Photoshop
Contrast may refer to: Science * Contrast (vision), the contradiction in form, colour and light between parts of an image * Contrast (statistics), a combination of averages whose coefficients add up to zero, or the difference between two means * Behavioral contrast, a phenomenon studied in psychology (behavior analysis) * Contrast agent, used to distinguish structures or fluids within a body, often shortened to just "contrast" Technology * Contrast ratio, a measure of a display system * Display contrast, of electronic visual displays Language * Contrast (linguistics), expressing distinctions between words * Contrast (literary), describing the difference(s) between two or more entities Arts and entertainment Music * The Contrast (band), an English pop band formed in 1999 * Contrast (music), the difference between parts or different instrumental sounds * High Contrast, Welsh music producer and artist born in 1979 Albums * Contrast (Tages album), ''Contrast'' (Tages album), 1967 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the photographic film, film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by Chemical synapse, synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rod cell, rods and cone cell, cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Mean Square
In mathematics, the root mean square (abbrev. RMS, or rms) of a set of values is the square root of the set's mean square. Given a set x_i, its RMS is denoted as either x_\mathrm or \mathrm_x. The RMS is also known as the quadratic mean (denoted M_2), a special case of the generalized mean. The RMS of a continuous function is denoted f_\mathrm and can be defined in terms of an integral of the square of the function. In estimation theory, the root-mean-square deviation of an estimator measures how far the estimator strays from the data. Definition The RMS value of a set of values (or a continuous-time waveform) is the square root of the arithmetic mean of the squares of the values, or the square of the function that defines the continuous waveform. In the case of a set of ''n'' values \, the RMS is : x_\text = \sqrt. The corresponding formula for a continuous function (or waveform) ''f''(''t'') defined over the interval T_1 \le t \le T_2 is : f_\text = \sqrt , and the R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Frequency
In mathematics, physics, and engineering, spatial frequency is a characteristic of any structure that is periodic across position in space. The spatial frequency is a measure of how often sinusoidal components (as determined by the Fourier transform) of the structure repeat per unit of distance. The SI unit of spatial frequency is the reciprocal metre (m−1), (11 pages) although cycle (rotational unit), cycles per (c/m) is also common. In image-processing applications, spatial freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weber–Fechner Law
The Weber–Fechner laws are two related scientific law, scientific laws in the field of psychophysics, known as Weber's law and Fechner's law. Both relate to human perception, more specifically the relation between the actual change in a physical Stimulus (physiology), stimulus and the perceived change. This includes stimuli to all senses: vision, hearing, taste, touch, and smell. Ernst Heinrich Weber states that "the minimum increase of stimulus which will produce a perceptible increase of sensation is proportionality (mathematics), proportional to the pre-existent stimulus," while Gustav Fechner's law is an inference from Weber's law (with additional assumptions) which states that the intensity of our sensation increases as the logarithm of an increase in energy rather than as rapidly as the increase. History and formulation of the laws Both Weber's law and Fechner's law were formulated by Gustav Fechner, Gustav Theodor Fechner (1801–1887). They were first published in 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tour Eiffel Notre-Dame+contrast
Tour or Tours may refer to: Travel * Tourism, travel for pleasure * Tour of duty, a period of time spent in military service * Campus tour, a journey through a college or university's campus * Guided tour, a journey through a location, directed by a guide * Walking tour, a visit of a historical or cultural site undertaken on foot Entertainment * Concert tour, a series of concerts by a musical artist or group of artists in different locations * Comedy tour, an organized trip where comedians travel to various places; see List of stand-up circuits * Touring theatre, independent theatre that travels to different venues Sports * Professional golf tours, otherwise unconnected professional golf tournaments * Tennis tour, tennis played in tournament format at a series of venues * Events in various sports named the Pro Tour (other) * Tour de France ('), the world's biggest bicycle race Places * Tour-de-Faure, Lot, France * Tour-en-Bessin, Calvados, France * Tour-en-Sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tour Eiffel Notre-Dame
Tour or Tours may refer to: Travel * Tourism, travel for pleasure * Tour of duty, a period of time spent in military service * Campus tour, a journey through a college or university's campus * Guided tour, a journey through a location, directed by a guide * Walking tour, a visit of a historical or cultural site undertaken on foot Entertainment * Concert tour, a series of concerts by a musical artist or group of artists in different locations * Comedy tour, an organized trip where comedians travel to various places; see List of stand-up circuits * Touring theatre, independent theatre that travels to different venues Sports * Professional golf tours, otherwise unconnected professional golf tournaments * Tennis tour, tennis played in tournament format at a series of venues * Events in various sports named the Pro Tour (other) * Tour de France ('), the world's biggest bicycle race Places * Tour-de-Faure, Lot, France * Tour-en-Bessin, Calvados, France * Tour-en-Solog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viewing Cone
The viewing cone is the set of effective viewing directions of a Computer monitor, visual display, as seen from the eye. This collection of angles resembles a generalized cone. The concept has been introduced as an international standard ISO 13406-2, which defines it as the ''range of viewing directions'' that can safely be used for the intended task without "reduced visual performance". This standard describes a complex procedure which evaluates the viewing cone from measurements of luminance and chromaticity versus direction of observation. ISO 13406-2 introduces 4 ''viewing direction range classes'', from a wide viewing cone, for many simultaneous observers, to the so-called "privacy display", with a severely limited viewing cone. Compliance routes for different display applications can now be found in the successor standard ISO 9241#ISO-9241-3xx, ISO 9241-300. Viewing direction When a visual display device, display with non-vanishing size is seen by an observer, every point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Display Contrast
In physics and digital imaging, contrast is a quantifiable property used to describe the difference in appearance between elements within a visual field. It is closely linked with the perceived brightness of objects and is typically defined by specific formulas that involve the luminances of the stimuli. For example, contrast can be quantified as ΔL/L near the luminance threshold, known as Weber contrast, or as LH/LL at much higher luminances. Further, contrast can result from differences in chromaticity, which are specified by colorimetric characteristics such as the color difference ΔE in the CIE 1976 UCS (Uniform Colour Space). Understanding contrast is crucial in fields such as imaging and display technologies, where it significantly affects the quality of visual content rendering. The contrast of electronic visual displays is influenced by the type of signal driving mechanism used, which can be either analog or digital. This mechanism directly influences how well th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encyclopædia Britannica 2006 Ultimate Reference Suite DVD
An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into articles or entries that are arranged alphabetically by article name or by thematic categories, or else are hyperlinked and searchable. Encyclopedia entries are longer and more detailed than those in most dictionaries. Generally speaking, encyclopedia articles focus on ''factual information'' concerning the subject named in the article's title; this is unlike dictionary entries, which focus on linguistic information about words, such as their etymology, meaning, pronunciation, use, and grammatical forms.Béjoint, Henri (2000)''Modern Lexicography'', pp. 30–31. Oxford University Press. Encyclopedias have existed for around 2,000 years and have evolved considerably during that time as regards language (written in a major international or a vernacular language), size (few or many volumes), intent ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptive Field
The receptive field, or sensory space, is a delimited medium where some physiological stimuli can evoke a sensory neuronal response in specific organisms. Complexity of the receptive field ranges from the unidimensional chemical structure of odorants to the multidimensional spacetime of human visual field, through the bidimensional skin surface, being a receptive field for touch perception. Receptive fields can positively or negatively alter the membrane potential with or without affecting the rate of action potentials. A sensory space can be dependent of an animal's location. For a particular sound wave traveling in an appropriate transmission medium, by means of sound localization, an auditory space would amount to a reference system that continuously shifts as the animal moves (taking into consideration the space inside the ears as well). Conversely, receptive fields can be largely independent of the animal's location, as in the case of place cells. A sensory space can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
