Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Accuracy

accuracy is the degree of precision in the positioning of lines and dots on paper. Many factors affect the accuracy with which the geographical features can be drawn on a map: the scale, the quality of the data source, the thickness of the lines adopted in the representation.

Actuality

is a measure of overall quality of a mapping which measures the percentage change between the time of detection and the current date.

Address matching

literally address detection, is an alternative system for data geocoding. With some software you can indeed build a system of reference that allows the identification of a point than through classical coordinate systems (eg. Latitude and longitude) but by indications of addresses (street, house number, etc..) on, for instance, a road graph.

ADSL

ADSL stands means Asymmetric Digital Subscriber Line and is a technology that allows you to convert analog phone line (the traditional twisted pair copper) in a high speed digital line for an ultra-fast Internet access. ADSL is ideally suited to the way of browsing the Internet and to the use of multimedia content, both characterized by a greater flow of data from the network towards the user (downstream) and a smaller amount of data and control signals sent by the user to the network (upstream), which is why it is called 'asymmetric'.

Aerophotogrammetric restitution

procedure which allows, using special instruments (analogue or digital photorestitutor), to build a map (both on paper and digital) of a portion of land by stereoscopic aerial photographs.

Algorithm

algorithm well-defined complex instructions or operational requirements that govern the behavior of an operator (mechanical, electronic or human) to solve a problem. In a software corresponds to a set of instructions to the computer.

Arc

linear element stored in vector format consists of a begin pair of coordinates (starting node), a final pair of coordinates (end node) and a series of coordinate pairs such intermediate vertices. Each arc has a direction and a length. By combining several arcs together by the nodes it is possible to build some usable graphs, for example, for many types of analysis (road, hydrographic, etc.).

Area compared

see buffer.

Attribute

descriptive information associated with a geographic object and that characterizes it. Generally, in the GISs, indicates the features not graphics of the element or those that cannot be represented in the scale of acquisition. For example, they might be attributes of a linear element (arc) which represents a road: the type of pavement, the average number of vehicles in transit, width, etc..

B

Backup

process by which you can save the entire patrimony of the data on media that ensure its preservation over time.

Band

frequency range of the electromagnetic spectrum in which, for example, the satellite sensors operate which are able to separate the information collected in the visible and infrared (temperature, humidity, etc.).

Base mapping

is the set of maps covering a certain territory, built with topographic and photogrammetric techniques, that represent the planimetries (watercourses, roads, railways, bridges, houses, etc.) and the altimetry consists of elevation points or curves of level.

BIL (Band Interleaved by Line)

is a standard format for raster data, in which information on the various bands are sequencing at the line level (the value of the pixels of the first line of the first band is followed by the match in the second band and so on, before continuing with the second line).

BIP (Band Interleaved by Pixel)

is a standard format of raster data, in which information on the various bands are sequencing at the pixel level (the value of the pixel of the first band is followed by the match in the second band and so on, before continue with the second pixel).

Bit

character that represents one of the 2-digit binary system: 0 or 1. It is the smallest unit of information and also indicates the smallest storeable unit. The name derives from a contraction of BInary diglT.

Buffer, buffering

buffering is an analysis process belonging to the scope: topological overlay. It lets you create polygons around elements (areas of respect). With it you can determine for example the not building area around roads with heavy traffic or areas around military or industrial zones, etc.. The size and therefore the radius of the respect area can be defined by the attributes of the items buffered for example on the streets (linear elements) the width or depth of trade for the antennas (elements point) the power of signal for industrial zones (elements ranges) the pollution load.

Byte

array of 8 bits: it is the smallest addressable unit in memory and it corresponds to the codification of an alphanumeric character.

C

CAD (Computer Aided Design)

is a family of systems and software for computer-aided design, used for architectural design, civil relief, the mechanical and parametric design, the metric calculation, the design of wiring diagrams, etc..

Check point

a point of known coordinates recognizable on the image or the map that you want to georeference. Georeferencing algorithms usually require more control points (at least four) for each sheet.

Class of elements

a layer may contain several classes of information elements. Each geographic data can be represented by a class of elemets such as an arc, a node, a polygon, an annotation, etc.. Each class of elements may have attributes associated with tables.

Classification

analytical procedure for the determination of classes that group homogeneous types of elements, such as the land use, the type of roads, the urbanization, etc..

Coherence

see logical congruence.

Compression

is a technique for compressing raster images to store them in less space. They used various compression algorithms, which generally must be followed by a decompression before the image can be used again.

Conformal projections

are projection systems generally used for mapping of oceans and atmosphere since they allow to maintain faithful to reality, the angular relationships between the elements and, therefore, the wind direction or against the weather.

Connection

is a topological properties of the elements of a GIS is represented by the sharing of an arc between two areas.

Connection

is a topological property of the elements of a GIS represented by sharing a node between two arcs.

Curves of level

is the set of constant quota lines that describes the the planimetric land usually obtained by manually or automatically interpolation from a TIN, a DEM or DTM.

D

Data Bank

see database.

Database

database (or archive) means a set of information of different kinds. These data are organized according to precise criteria which allow a rapids consultation.

DBMS (Data Base Managment System)

system for storing and searching for information in a database.

Decompression

see compression.

Default

means the default choices made by the system (or program) in the absence of an explicit indication of the user.

DEM (Digital Elevation Model)

is a raster data model that represents the elevation of the land. Can be generated from a plain rated or curves of level and is generally used for conducting analysis of visibility, generate longitudinal profiles, perform analysis of slope and exposure, etc..

Derived thematic maps

they are maps obtained by interpolation of observed values or maps obtained from the analysis and correlation of additional derived thematic maps.

Desktop

feature of computers and programs that can be placed on a desk and used by the user without requiring additional supports.

DIGEST

is an international standard that defines a data format typically used for topological data interchange among GIS.

Digital mapping

is the digital version of a traditional map, the location and description of the elements are stored in a series of files on your computer. To locate the position of the geographical elements is used a system of Cartesian coordinates x, y or x, y, z: each point is represented with a single pair of coordinates x, y, and each line is stored as an ordered set of coordinates x, y; each area is stored as an ordered set of x, y coordinates that define the outer segments of the closed figure. With coordinates x, y is possible to represent points, lines and polygons as lists of coordinates, rather than as a drawing. In most cases, the storage elements using geographic coordinates of the real world: these coordinates represent a real location on the surface of the earth, in one of the so many coordinate systems. The relationship between geographic elements are expressed on a digital map, with the use of topology. The characteristics of the geographical features are stored in a computer file, usually called table, as a set of numbers and characters.

Digital

digital data information expressible through integers that can be stored on a magnetic support.

Digitizer

hardware device used for the manual acquisition of graphical information (maps, documents, etc..) in vector format. It allows an operator to draw with a cursor all the graphic elements that compose the document or the map to be scanned.

DIME (Dual Indipendent Map Encoding)

is a standard format for vector data used by the U.S. Census Bureau and had replaced since 1990 by TIGER.

Directory

logic partition of a mass storage, in which a user can store a set of files usually about a specific topic.

DTM (Digital Terrain Model)

literally digital terrain model, raster or vector, see DEM and TIN.

DXF (Drawing eXchange File format)

format for not topological vector data typical of the CAD used by AutoCAD, but also by many GIS, to exchange data.

Dynamic segmentation

is an extension of the data model of a GIS that allows to overlap to the physical topological structure a new physical topology, defined in a logical manner, without the need to change the data in the database. For example, data relating to a road network such as the state of the pavement, the frequency of accidents, speed limits can all be associated to the single traits (route) of the same graph that represents the road network.

E

Eliosynchronous orbit

the name comes from the fact that this orbital configuration the angle formed by joining the Sun - the center of the Earth and the orbital plane of the satellite is kept constant over time. This makes the passage of the satellite occurs at the same time for the same latitudes.

Entity

discontinuous objects belong to the category of entity, spatially delimited by precise boundaries and, possibly, characterized by specific attributes. Examples of entities are the allocation of territory in normative areas or the graph description of a network of transport infrastructure.

Equidistant projections

are projection systems that preserve the distances among determined points.

Equivalent projections

are projection systems that are generally used in cases where the user must compare the spatial dimensions (eg forests or areas for agriculture).

ERDAS

is the name of a software manufacturer for processing remotely sensed images used also to define a owned format for raster data.

Esaustivity

is a measure of overall quality of a cartography that measures the excess or the lack of information.

F

Field

in a table of attributes, indicating a location within a record dedicated to a single characteristic of each element of the table. See table of attributes.

G

Gauss-Boaga

is a system of coordinates in inverse cylindrical projection typically used for the cartography of the territory in Italy (IGMI, Inventory, Regional Technical Papers, etc..).

GB (GigaByte)

unit of information in the memory, equal to one billion bytes (characters).

Genealogy

is a description of the overall quality of a mapping and it corresponds to all the information on the sources and on the treatments.

Generalization

algorithm present in many softwares GIS and CAD that allows you to prune the number of the vertices that compose one or more linear elements. The operations of generalization are necessary to prune a data and move it to a larger scale, removing the vertexes and making it the most linear element with the level of accuracy defined.

Geographic map

is a graphical representation of geographic elements or other spatial phenomena (lakes, rivers, roads, cities ...) which provides two types of information about the area represented: the position and the aspect. The location allows you to understand where a particular geographical feature is on the surface of the earth and what are its relationships with the other elements. The issue illustrates us both the qualitative characteristics (name, type ...) and those quantitative (area, length ...) of the represented element. Each map shows, in addition to descriptive and spatial information, some technical features that define and determine its use. These features include the scale, the accuracy, the projection system, the system of coordinates.

Geographic projection

is a system of global projection, historically used for first, based on the earth's subdivision in meridians and parallels. Its system of reference, latitude / longitude, measure the angular distances, respectively, starting from the reference plane of the equator and from the meridian of Greenwich.

Geographical Data Base

database dedicated to information of such territorial.

Geographical database

database dedicated to information of such territorial.

Geomarketing

GIS application that displays the contents of a database, coupled by a geocode (municipality code, address, sales area, zip code, etc..) to a map, to view marketing phenomena affecting the territory and develop spatial analysis (distribution, counters, basins of use, compared with demographic, etc..).

Geometric congruence

is a parameter of local quality of a cartography defined as the absence of errors of form and position that cannot be detected without direct verification in the field.

Georeference

software procedure that consists of positioning, by points at known coordinates (control points), vector data or raster image in its respective area of real territory, according to a fixed reference system.

Geostationary satellite

an orbiting satellite above the equator at a height of about 36,000 km., whose period of revolution around the Earth coincides with a time of Earth's rotation. For this reason the satellite constantly see the same portion of the Earth (such as METEOSAT). Is also called geosynchronous satellite.

Geosynchronous satellite

see geostationary satellite

GIS (Geographical Information System)

a complex set of hardware, software, and human to acquire, to process, to analyze, to store and to return, in a graphical and alphanumeric format, data related to a territory.

Global quality

set of parameters that characterizes the quality of a geographical database as a whole (exhaustiveness, current affairs, genealogy).

GPS (Global Positioning System)

is a system that allows, through a receiver, a dedicated software and a constellation of satellites to determine the position on the ground and the altitude of a point, with an accuracy that varies from a few millimeters to a few meters depending on the type of equipment and operating procedures of relief used.

Graph

is a related set of arcs that, in a GIS, generally describes a network (road, hydrographic, technology, etc..). The GIS software have generally functions of analysis and modeling of networks based on a graph (optimal path, optimization of stops, location analysis, etc..).

GRASS (Geographical Resource Analysis Support System)

is the name of a software for image processing used to define the corresponding raster data format.

GRID

is the name of the extension of ESRI ARC/INFO processing databases in raster format and is also used to define the corresponding data format.

GUI (Graphical User Interface)

software for creating and managing graphical user interfaces. Allows the user to access the system functions through the mouse also and through simple graphical objects (buttons, scroll lists, icons, images, etc..).

I

IGES (Initial Graphics Exchange Standard)

ASCII vector data format not topological and uncompressed, typical of the CAD, made by the U.S. Department of Commerce and used, sometimes by GISs, to exchange data.

Image processing

set of activities concerning the development of images in raster format. Many of the techniques used in this discipline requires complex mathematical procedures with the objective to determine the phenomena described by the imagea such as, for instance in GIS, pollution, humidity and temperature to the ground, vegetation, etc..

Informatic system

Set of computer system hardware and software that characterize an information system.

Informative system

Set of information, system equipment, procedures and people who have the task of collecting, organizing, selecting, storing and communicating data concerning the activities of an organization. Its aim is to provide operational decision makers all the information necessary to make the best choices possible.

Interpolation

technique through which it is possible to build a linear path, of which it is known only a discrete number of points. Constructing a grid of points you can get an estimate of the position of points that you do not possess.

ISDN

stands for 'Integrated Services Digital Networks', and is a term created by the organization ITU-T. It is, in practice, a total conversion to digital of the actual telephone net, using the existing wiring and switching equipment.

Isogonia

property of some projection systems to maintain unchanged the measures of the angles among straight lines.

K

KB (Kilobyte)

unit of information in memory, equal to one thousand bytes (characters).

L

Lambert

is a conic projection that can be conforming or equivalent, particularly used in the U.S. by the Geological Survey, in Italy and in France.

LANDSAT

family of satellites designed for observing the earth through multispectral sensors.

Latitude

see geographical projection.

Layer, Informative layer or Geographical layer

is the basic unit of data management and defines the positional and thematic attributes for elements of map of a given area. The informative layer or geographical layer are the set of homogeneous elements that compose a map, such as roads, rivers, forests, etc..

Layer

see informative layer.

Legend

is a tool on the papers that associates the graphic symbols used to the single tematismis, for readability.

Library

set of software modules common to several programs.

Local quality

set of quality parameters for each individual mapping element (metric precision, resolution, semantic precision, consistency or logical consistency, geometric congruence).

Logical congruence

is a parameter of local quality of a mapping defined as the absence of inconsistency detected independently of a case in reality (a building on a street, two curves of level that intersect, an attribute with a value outside the indicated range, etc..).

Logical expression

consists of logical operators, operands and pairs of brackets, organized according to syntactic rules specified, so as to express a group of operations that provide a single result. It is used to make selections between classes of elements in the process of data analysis.

Logical operator

entities used to formulate, for instance in a database, the logical conditions for the selection of records in according with the values of the fields. See SQL.

Longitude

see geographical projection.

M

Mass memory

device that allows the permanent storage of data (generally the hard drive of the computer).

MB (Megabyte)

unit of information in memory, equal to one million bytes (characters).

Metadata

are information about the data sets in a database. A set of metadata can be considered consistent when, in the way most synthetic possible, provides an adequate description of the content, quality and characteristics of the data.

Metric precision

is a quality parameter of a local mapping defined as the difference in position of a point on the map compared to its real position in the national cartographic reference system.

Mosaicing

is the set of operations that, within the GIS, allows you to merge multiple maps in digital format to create a territorial continuity.

N

Nadir

the vertical drawn from any point within the earth's surface, where is the observer, meets the celestial sphere in two opposite points. Nadir is what lies below the horizon, the other, which is above, is the zenith.

Native format

source format in which an object (program, file, data) was originally written.

Node

is a point with topological characteristics describing the beginning or end of an arc.

Nominal scale

is a parameter that defines the scale of reference for a digital mapping according to the corresponding scale of a traditional cartography realized following the same requirements of metric accuracy.

NTF (National Transfer Format)

data format used for interchange of data between topological GIS (adopted by the Italian Inventory).

O

Object

physical or logical entity defined by a set of characteristics and rules of behavior which express the state of static or dynamic. For example in a GIS object could be the set of a telephone plant, its connections and its related management procedures.

Open source

mode of software distribution such that the programming code is issued along with the program.

Orthogonalization

see recording.

Orthophotography

technology for the production of orthophotographs employing tools and procedures can provide a metric representation of the land in the form of photographic images.

Overlay, topological overlay

procedure of spatial analysis that allows to overlap and to intersect the layers uniting the information associated with each of them to produce a new layer of synthesis.

P

Pan

positioning function of the graphic images on the screen depending on the choice of a new central point or on the scroll of the graphic window.

Password

keyword, which is the access code for a given user name.

Path

ordered set of nodes and arcs that connect origin and destination.

Photogrammetric

see aerophotogrammetric restitution.

Photointerpretation

technique that allows experts to determine and classify spatial phenomena by reading aerial photographs or remotely sensed images such as, for example, vegetation types, determination of faults or updating of existing cartographic maps.

Photoplain

mosaic of aerial photos straighten particularly applicable to flat land.

Pixel

contraction of picture element, is the basic component of a raster image characterized by an associated value.

Plotter

equipment that is used to draw graphs or drawings prepared by a computer. Can be a pen, electrostatic, inkjet or thermal transfer.

Plug-in

is the addition of some option / application to another application. Between sheets of Excel, for example, consists of inserting 'specific options' to see particular sheets.

Point

geometric element used to define the position of items that are punctiform in the scale of acquisition, defined by a pair of coordinates (x, y) and eventually by a quota (z).

Polygon

closed area delimited by arcs.

Primary key

one or more fields whose values uniquely identify a row in a table of the database.

Process

the term process is intended to indicate an ordered sequence of operations whose final purpose is to obtain new data or revise existing ones in a form which facilitates the interpretation and evaluation. Fundamental elements for the definition of a process are the data, the operators and the links between the operators to determine their order of execution.

Projection systems

are systems that can represent the surface almost spherical Earth on a plane, keeping some conformity (isogon, equivalence, equidistance, etc..): the best known are the Geographical one, the UTM, the Gauss-Boaga and the Lambert others are the Conic, the Polar, the Stereographic, the Cylindrical and the Planar also variously combined.

Projection

see geographic projection.

Q

Query

set of SQL statements that allow you to extract information from the geographical and alphanumeric database

R

Raster image

any image can be thought of as consisting of a set of small equal areas (pixels), arranged along lines and columns, such as to constitute a matrix. The values associated with each cell may express both graphical information (color, shade of gray, etc.) and descriptive (temperature, slope, etc..).

Rasterization

operation that allows to automatically obtain a raster image from vector image or paper documents (scanner).

Record

group of contiguous positions of information (fields), including uneven, which can be accessed according to different modes. See table of attributes.

Recording

are the necessary techniques to georeference and rectify raster images. In fact, aerial photos and satellite images, as well as having to be positioned correctly (collimating the coordinates of known points on the ground with those of image objects) are also to be re-calculated using the angle from which it was taken.

Reference system

each projection has its own reference system from which it starts to calculate the distances. For example, the geography projection uses as a reference the intersection of the Greenwich meridian and the Equator, the UTM provides six degrees of predetermined segments called fused these divided into zones (for Italy 32, 33 and 34), the Gauss-Boaga, starts from Monte Mario (Rome) and uses coordinates conventionally measured in kilometers from 1500 to 2520 left and right of the meridian of reference.

Regression

is an interpolation between different statistical surveys, such that a correlation is identified between the data, often due to geometric curves.

Relational database

method of structuring data in the form of a collection of tables that are logically related to each other through shared fields. Each element can be found in relation to the table name, the name of the field, and the value of the primary key.

Relationship

in a relational database the relationship is the logical link among two tables of data through the primary and secondary keys.

Resolution

is a measure of quality local of a mapping and it corresponds to the size of the smallest detail represented in the mapping vector and to the length of the side of the cell (pixel) in raster format.

RLC (Run Lenght Coded)

is a standard of raster data compression. See compression.

Route

element at the base of the dynamic segmentation to which can be associated attributes. The route can be constituted by a portion or subset of arcs without its beginning or end node must coincide with the start or end of an arc.

Routine

compilation of a sequence of actions necessary to perform an operation, which are invoked by the program whenever it is necessary to perform such operation.

S

Scale

indicates, in practice, how many times a portion of the land surface has been reduced in order to be represented on a sheet of paper. It is expressed, in general, as the ratio between a distance on the paper and the corresponding distance on the ground. The ratio of scale used for a map determines the information content and the size of which can reasonably be represented. We define large-scale maps (1:500, 1:1000, 1:2000), medium scale (1:5000, 1: 10000) and small-scale (1:25000 onwards).

Scanner

hardware device for the automatic acquisition in digital format of graphic elements (maps, photos, pictures, etc..). Graphical information is stored in raster format. It is possible nevertheless through special tools software to convert such information in vector format (vectorization).

Secondary key

one or more fields whose values uniquely identify a row in another table of the database through a relationship with the primary key.

Semantic precision

is a quality parameter of a local mapping defined as the correspondence between reality and the qualitative attribute associated with the object.

Sensor

detector used in remote sensing that converts electromagnetic radiation into electrical signals interpretable. Active sensors measure the energy reflected by the objects, but emitted from a device on board. Active radar sensors, in particular, are characterized by the fact that they can operate even in the presence of weather disturbances, such as SAR (Syntetic Aperture Radar) on the satellite ERS-1. Passive sensors measure the energy emitted by the sun and reflected by the earth or energy spontaneously emitted from objects, such as the TM (Thematic Mapper) and MSS (Multi Spectral Scanning) on Landsat 5.

Shortest path

is an algorithm of analysis that can determine within a graph, the path that optimizes a parameter in the networks, the impedance or that determines the difficulty of crossing the auction of the graph, such as a road network the route that minimizes the distance or time within the limits of speed, track, maximum weight allowed, etc..

Simple thematic maps

maps entered into the system and here used without modification or GIS maps created internally but still represent 'primitive' maps, not derived from processing of other elements of the database.

SIT (Territorial Informative System)

italian acronym corresponding to the Anglo-Saxon GIS.

Spatial data

data characterized by a geographical reference.

Spatial relationships

see topology, contiguity and connection.

SPOT (Système Probatoire d’Observation de la Terre)

satellite family for multispectral remote sensing system with mobile aim system. The definition on the ground is 20 meters for the multispectral and 10 meters for the panchromatic. The first launch of this French system dates back to 1986.

SQL (Structured Query Language)

structured language for the consultation and the selection of information in a relational database.

Symbols

are the graphical primitives used to represent on paper or video phenomena occurring in the territory. The symbols can be landing-nets to prime an area, linear (continuous, dashed, drawn - point, etc..), to trace linear features or point (cross, star, triangle, etc..), to indicate a specific location. Each symbol can be designed in a wide variety of colors.

T

Table of attributes

tables are an integral part of the layer information. Each table is for a homogeneous group of geographic map (roads, rivers, contours, etc..) and consists of a variable number of rows and columns. Each row (record) contains a description of a single geographical feature and each column (field or attribute) stores a specific type of information. The characteristics of the geographical elements are generally translated into numeric or alphabetic, before being inserted in the relevant table.

Template

in GISs, template are graphic elements (usually linear) that belong to different layers of information. The presence of templates greatly complicates the management of geographic database, for example by imposing rules for updating the data. If you update some elements of a layer information should be updated in all layers that contain words related to the same elements. A typical example is the limit for buildings in the layer on the building, which coincides with the start of the pavement layer on the streets.

Territorial continuity

means a continuous geographical coverage, in alternative to the classical subdivision by map sheets.

Thematism

representation of a raster or vector maps in which points, lines or surfaces are associated with symbols, textures, or colors that represent the result of analysis of quality (land use, zoning areas, intensity of traffic on a road, etc..).

Theodolite

topographical tool used for geodetic measures.

TIFF (Tag Image File Format)

is a standard format for the interchange of raster data.

TIGER (Topologically Integrated Geographic Encoding and Referencing)

is a standard format for vector data used by the U.S. Census Bureau since 1990 in place of DIME.

TIN (Triangulated Irregular Network)

literally irregular network of triangles, is a three-dimensional model of the terrain generated from a sparse set of points listed (rated plan) consists of a network of triangles as equiangular, equilateral, and therefore, not possible since which can interpolate contours, conduct analysis of visibility, generate longitudinal profiles, perform analysis of slope and exposure, etc..

Topology

is a set of rules to define explicitly the relationships, the relationships of connection and contiguity between spatial elements and to link these elements with their descriptions (attributes). In a topological data model, for example, you can recognize and identify the areas adjoining the lines that demarcate each area (boundaries).

UMTS

is the acronym of Universal Mobile Telephone System and stands for the third generation of mobile telephone services. The analogical network was the first generation of mobile telephony, the GSM network, which is still active, is the second. The new UMTS technology seeks to improve and expand existing capacity of mobile technologies, radio and satellite, providing more capacity and a range of superior services. Through the new UMTS technology will be available a series of individual multimedia services, such as the association of the number of the person, and not to a number of customers or an office.

U

User-name

name by which the user is preventively identified to access a computer network, database or protected file.

User interface

is the set of tools, the purpose of which is the communication between the user and the procedures of the hardware and software system used.

UTM (Universal Transverse Mercatore)

is a cylindrical projection inverse adopted worldwide.

V

Vectorial

is a system for storing graphics data according to which the objects are stored according to the Cartesian coordinates of the points and lines that compose them.

Vectorialization

procedure that allows an automatic or semiautomatic way (ie, with the assistance of an operator) to draw a set of vectors from a raster image.

W

Wizard

installation programs or assisted creation of documents or applications, which guide the user step by step towards a final objective.

Z

Zenit

see nadir.

Zoom

enlarging or reducing video function (in, out) present in the most of graphic software.

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