Unsharp maskingUnsharp masking (USM) is an image sharpening technique, first implemented in darkroom photography, but now commonly used in digital image processing software. Its name derives from the fact that the technique uses a blurred, or "unsharp", negative image to create a mask of the original image. The unsharp mask is then combined with the original positive image, creating an image that is less blurry than the original.
Dodging and burningDodging and burning are techniques used during the printing process to manipulate the exposure of select areas on a photographic print, deviating from the rest of the image's exposure. In a darkroom print from a film negative, dodging decreases the exposure for areas of the print that the photographer wishes to be lighter, while burning increases the exposure to areas of the print that should be darker.Zone SystemThe Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Fred Archer. Adams described the Zone System as "not an invention of mine; it is a codification of the principles of sensitometry, worked out by Fred Archer and myself at the Art Center School in Los Angeles, around 1939–40". The technique is based on the late 19th-century sensitometry studies of Hurter and Driffield.
High dynamic rangeHigh dynamic range (HDR), also known as wide dynamic range, extended dynamic range, or expanded dynamic range, is a signal with a higher dynamic range than usual. The term is often used in discussing the dynamic ranges of images, videos, audio, or radio. It may also apply to the means of recording, processing, and reproducing such signals including analog and digitized signals.Dynamic rangeDynamic range (abbreviated DR, DNR, or DYR) is the ratio between the largest and smallest measurable values of a specific quantity. It is often used in the context of signals, like sound and light. It is measured either as a ratio or as a base-10 (decibel) or base-2 (doublings, bits or stops) logarithmic value of the ratio between the largest and smallest signal values.
Standard-dynamic-range videoStandard-dynamic-range video (SDR video) is a video technology which represents light intensity based on the brightness, contrast and color characteristics and limitations of a cathode ray tube (CRT) display. SDR video is able to represent a video or picture's colors with a maximum luminance around 100 cd/m, a black level around 0.1 cd/m and Rec.709 / sRGBcolor gamut. It uses the gamma curve as its electro-optical transfer function.
Map (mathematics)In mathematics, a map or mapping is synonymous to a function, though various branches add further nuances to differentiate them. The terms may have originated as from the process of making a geographical map: mapping the Earth surface to a sheet of paper. Maps and functionsThe term map may be used to distinguish some special types of functions, such as homomorphisms.
Digital image processingAlgorithmic processing of digitally-represented imagesDigital 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 and distortion during processing.
RadianceIn radiometry, radiance is the radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. Radiance is used to characterize diffuse emission and reflection of electromagnetic radiation, and to quantify emission of neutrinos and other particles. The SI unit of radiance is the watt per steradian per square metre (W·sr·m).
Computer graphicsComputer graphics (CG) deals with generating images and art with the aid of computers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven by computer graphics hardware. It is a vast and recently developed area of computer science.
High-dynamic-range televisionVideo and image technology for HDR displaysHigh-dynamic-range television (HDR-TV) is a technology that uses high dynamic range (HDR) to improve the quality of display signals. It is contrasted with the retroactively named standard dynamic range (SDR). HDR changes how luminance and colors in videos and images are represented in the signal, allowing brighter, more detailed highlights, darker, more detailed shadows, and more intense colors.
Liquid-crystal displayA liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not emit light directly but instead use a backlight or reflector to produce images in color or monochrome.
Cathode ray tubeA cathode ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams, which are directed and controlled to display images on a phosphorescent screen. The images may represent electrical waveforms on an oscilloscope, a frame of video on an analog television set (TV), digital raster graphics on a computer monitor, or other phenomena like radar targets. A CRT in a TV is commonly called a picture tube.*As an Amazon Associate I earn from qualifying purchases.