In computers, a printer driver or a print processor is a piece of software that converts the data to be printed to the form specific to a printer. The purpose of printer drivers is to allow applications to do printing without being aware of the details of each printer model. Printer drivers should not be confused with print spoolers, that queue print jobs, unix and other Unix-like systems such as Linux and OS X use CUPS, a modular printing system for Unix-like computer operating systems, which allows a computer to act as a print server. A computer running CUPS is a host that can accept print jobs from client computers, process them, Printer drivers are typically implemented as filters. They are usually named the front end of the printing system, backends are also used to determine the available devices. On startup, each backend is asked for a list of devices it supports, DOS supports predefined character devices PRN, LPT1, LPT2, and LPT3, associated with parallel printers supported in
Images may be two-dimensional, such as a photograph or screen display, or three-dimensional, such as a statue or hologram. They may be captured by optical devices – such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water. The word image is used in the broader sense of any two-dimensional figure such as a map, a graph. A volatile image is one that only for a short period of time. This may be a reflection of an object by a mirror, a fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or any other digital process. A mental image exists in a mind, as something one remembers or imagines. The subject of an image need not be real, it may be a concept, such as a graph, function. For example, Sigmund Freud claimed to have dreamed purely in aural-images of dialogs, a still image is a single static image, as distinguished from a kinetic image. Thi
A man creating an image of himself, in the form of a painting
An SAR radar image
acquired by the SIR-C/X-SAR radar on board the Space Shuttle Endeavour
shows the Teide
volcano. The city of Santa Cruz de Tenerife is visible as the purple and white area on the lower right edge of the island. Lava flows at the summit crater appear in shades of green and brown, while vegetation zones appear as areas of purple, green and yellow on the volcano's flanks.
A photograph or photo is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic medium such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scenes visible wavelengths of light into a reproduction of what the eye would see. The process and practice of creating photographs is called photography, the word photograph was coined in 1839 by Sir John Herschel and is based on the Greek φῶς, meaning light, and γραφή, meaning drawing, writing, together meaning drawing with light. The first permanent photograph, a copy of an engraving, was made in 1822 using the bitumen-based heliography process developed by Nicéphore Niépce. In 1829 Niépce entered into a partnership with Louis Daguerre and the two collaborated to work out a similar but more sensitive and otherwise improved process, after Niépces death in 1833, Daguerre concentrated on silver halide-based alternatives. He named this first prac
The earliest known surviving product of Nicéphore Niépce
process, 1825. It is an ink-on-paper print and reproduces a 17th-century Flemish engraving showing a man leading a horse.
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively, the fundamental problems of traditional cartography are to, Set the maps agenda and select traits of the object to be mapped. This is the concern of map editing, traits may be physical, such as roads or land masses, or may be abstract, such as toponyms or political boundaries. Represent the terrain of the object on flat media. This is the concern of map projections, eliminate characteristics of the mapped object that are not relevant to the maps purpose. This is the concern of generalization, reduce the complexity of the characteristics that will be mapped. This is also the concern of generalization, orchestrate the elements of the map to best convey its message to its audience. This is the concern of map design, modern cartography constitutes many theoretical and pract
A medieval depiction of the Ecumene
(1482, Johannes Schnitzer, engraver), constructed after the coordinates in Ptolemy's Geography
and using his second map projection. The translation into Latin and dissemination of Geography in Europe, in the beginning of the 15th century, marked the rebirth of scientific cartography, after more than a millennium of stagnation.
Photomapping involves the process of drawing a map from a photographic base. In all likelihood, computer map making, including analogue processing and it is quite reasonable to conclude that some form of photomap will become the standard general map of the future. Go on to suggest that, photomapping would appear to be the way to take reasonable advantage of future data sources like high altitude aircraft. The highest resolution aerial photomaps on GoogleEarth are approximately 2.5 cm spatial resolution images, the highest resolution photomap of ortho images was made in Hungary in 2012 with a 0.5 cm spatial resolution. Overhead photography has been applied for mapping surface remains and excavation exposures at archaeological sites. Hand held near nadir over head digital photographs have been used with geographic information systems to record excavation exposures, US Military Aerial Photomapping The ArcSat Approach to Archaeological Photomapping Archaeological Photography, Antiquity,10,
Capturing a digital overhead photograph for photomapping purposes
Using a pentop computer to photomap an archaeological excavation in the field
, a civilian UAV for aerial photography and photomapping with roll-stabilised camera head
A contour line of a function of two variables is a curve along which the function has a constant value. It is a cross-section of the graph of the function f parallel to the x, y plane. In cartography, a contour line joins points of elevation above a given level. A contour map is a map illustrated with contour lines, for example a map, which thus shows valleys and hills. The contour interval of a map is the difference in elevation between successive contour lines. More generally, a line for a function of two variables is a curve connecting points where the function has the same particular value. The gradient of the function is always perpendicular to the contour lines, when the lines are close together the magnitude of the gradient is large, the variation is steep. A level set is a generalization of a line for functions of any number of variables. Contour lines are curved, straight or a mixture of lines on a map describing the intersection of a real or hypothetical surface with one or m
A three-dimensional surface, whose contour graph is below.
The bottom part of the diagram shows some contour lines with a straight line running through the location of the maximum value. The curve at the top represents the values along that straight line.
Contour map labeled aesthetically in an "elevation up" manner.
Aerial photography is the taking of photographs of the ground from an elevated/direct-down position. Usually the camera is not supported by a ground-based structure, mounted cameras may be triggered remotely or automatically, hand-held photographs may be taken by a photographer. Aerial photography should not be confused with air-to-air photography, where one or more aircraft are used as chase planes that chase, Aerial photography was first practiced by the French photographer and balloonist Gaspard-Félix Tournachon, known as Nadar, in 1858 over Paris, France. However, the photographs he produced no longer exist and therefore the earliest surviving aerial photograph is titled Boston, as the Eagle, taken by James Wallace Black and Samuel Archer King on October 13,1860, it depicts Boston from a height of 630m. Kite aerial photography was pioneered by British meteorologist E. D. Archibald in 1882 and he used an explosive charge on a timer to take photographs from the air. Frenchman Arthur
Air photo of a military target used to evaluate the effect of bombing.
, "Nadar élevant la Photographie à la hauteur de l'Art" (Nadar elevating Photography to Art), published in Le Boulevard, May 25, 1862.
Reel-to-reel audio tape recording
Reel-to-reel or open-reel audio tape recording is the form of magnetic tape audio recording in which the recording medium is held on a reel, rather than being securely contained within a cassette. Reel-to-reel systems use a tape that is 1⁄4 inches in width and this compares to 0.15 inches wide and 1.875 inches per second for a cassette. By writing out the audio signal across more tape, reel-to-reel systems offer much higher fidelity. In spite of the tapes, less convenient use and generally higher cost media. Studer, Stellavox and Denon still produced reel to reel tape recorders in the 1990s, but as of 2014, only Nagra, Otari, originally, this format had no name, since all forms of magnetic tape recorders used it. The earliest machines produced distortion during the process which German engineers significantly reduced during the Nazi era by applying a bias signal to the tape. In 1939 one machine was found to make consistently better recordings than other ostensibly identical models, an
A reel-to-reel tape recorder (Sony TC-630), typical of those which were once common audiophile objects. Note the distinctive Scotch tape spool at left.
from a German radio station in World War II.
ZK-147, a vintage Polish
-made reel-to-reel tape recorder
7-inch reel of 1 ⁄ 4 -inch-wide (6.4 mm) recording tape, typical of non-professional use in the 1950s–70s. Studios generally used 10½ inch reels on PET film