Grafika un datorgrafika

Grafika (grieķu valodā γραφικός (grafikos) – kaut kas uzrakstīts):1) vizuāli attēli;2) skices un projekti uz kādas virsmas, lai ilustrētu un informētu.

Attēli, kuri tiek veidoti ar datoru, tiek saukti par datorgrafiku (computer graphics).

Attēls jāpielāgo lietošanai datorā

1

Vizualizācija (visualization)Glabāšana (storage)

Sameklēšana un izgūšana (search and extraction)Relāciju DBSRelaciju-objektu DBSXML DBS

Computer graphics are graphics created using computers and more generally, the representation and manipulation of graphics data by a computer.

The phrase “Computer Graphics” was coined in 1960 by William Fetter, a graphic designer for Boeing. Early projects like the Whirlwind and SAGE Projects introduced the display and interaction interface and introduced the light pen as an input device.

Computer graphics may be used in the following areas:Computational biology, Computational physics, Computer-aided design, Computer simulation, Digital art, Education, Graphic design, Infographics, Information visualization, Rational drug design, Scientific visualization, Video Games, Virtual reality, Web design

2

Grafiskās sistēmas (graphical systems)1. CAD/CAM (computer aided design/ computer aided manufacturing) sistēmas

2. GIS (geographical information systems) sistēmas

3. Vadības informācijas sistēmas (management information systems)

4. Pētniecības informācijas sistēmas (research information systems).

3

Datorizētā projektēšana (computer aided design (CAD))

1. Bieži sauc arī par datorizēto rasēšanu (computer aided drafting (CADD))

2. Datorsistēmu izmantošana projektu izstrādē, analizēšanai vai optimizēšanai.

4

Datorizētā ražošana (coputer aided manufacturing (CAM))

Ir datoru lietošana ražošanā, piemēram, tehnoloģisko procesu vadībā, materiālu uzskaites un sadales, operatīvās plānošanas u. c. darbu automatizācijā.

5

CAD/CAM sistēmas un apakšsistēmas6

a) projektēšana (design)

b) izstrāde (manufacturing)

Ģeogrāfija un ģeometrija

7

Locations on the Earth’s surface is usually marked using the longitude and latitude.

8

As seen in the above figure, a one degree longitude difference differs greatly depending on the latitude. A longitude 1° from the equator is 111.321 km, but longitude 1° from latitude 60° is only 55.802 km.

9

GIS sistēmas

10

Vadības informācijas sistēmas (management information systems) ar grafikas izmantošanu"A picture is worth a thousand words" refers to the notion that a complex idea can be conveyed with just a single still image. It also aptly characterizes one of the main goals of visualization, namely making it possible to absorb large amounts of data quickly.

11

Datorgrafika pētniecības sistēmās

12

13

14

15

Skaitļošanas ģeometrija (computational geometry)

Computational geometry is a branch of computer science devoted to the study of algorithms which can be stated in terms of geometry.

The main branches of computational geometry are:

1. Combinatorial computational geometry, also called algorithmic geometry, which deals with geometric objects as discrete entities. A groundlaying book in the subject by Preparata and Shamos dates the first use of the term "computational geometry" in this sense by 1975.

2. Numerical computational geometry, also called machine geometry, computer-aided geometric design (CAGD), or geometric modeling, which deals primarily with representing real-world objects in forms suitable for computer computations in CAD/CAM systems.

16

Skaitļošanas ģeometrijas problēmas

1. Ģeometrijas objekti kā diskrētas vienības (geometric objects as discrete entities)Problēma: nepārtrauktā telpa (reālā dzīve) un diskrētā telpa (datori)

-----------------------------------------------------------------------------------------------------------

17

2. The convex hull or convex envelope of a set X of points in the Euclidean plane or Euclidean space is the smallest convex set that contains X.

3. Line segment intersection problem supplies a list of line segments in the plane and asks us to determine whether any two of them intersect, or cross.

4. A Delaunay triangulation for a set P of points in a plane is a triangulation DT(P) such that no point in P is inside the circumcircle of any triangle in DT(P). Delaunay triangulations maximize the minimum angle of all the angles of the triangles in the triangulation; they

tend to avoid skinny triangles. The triangulation is named after Boris Delaunay for his work on this topic from 1934.

5. Closest point pair problem is a problem of computational geometry: given n points in metric space, find a pair of points with the smallest distance between them.

6. The Euclidean shortest path problem: is given a set of polyhedral obstacles in a Euclidean space, and two points, find the shortest path between the points that does not intersect any of the obstacles.

7. Polygon triangulation is the decomposition of a polygonal area (simple polygon) P into a set of triangles, i.e., finding the set of triangles with pairwise non-intersecting interiors whose union is P.

18

Vektoru un rastra grafika (vector and raster graphics)

In computer graphics, a raster graphics image or bitmap is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats.Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon(s), which are all based on mathematical equations, to represent images in computer graphics.

19

Vektoru grafika (objekti un telpa)

Rastra grafika

20

Grafisko datu standarti

This basic model is defined in the Open Geospatial Consortium (OGC) “Simple Features for SQL” (SFSQL) specification and defines the playing field shared by all the particular spatial database implementations we will be discussing.The SFSQL specifies the particular rules for building valid geometries, the legal representations of geometries in both ASCII and binary form, and a set of basic functions for constructing, inspecting, measuring and manipulating geometries.

Simple Features (officially Simple Feature Access) is both:1) an Open Geospatial Consortium (OGC);2) an International Organization for Standardization (ISO) standard ISO

19125 that specifies a common storage model of mostly two-dimensional geographical data (point, line, polygon, multi-point, multi-line, etc.)

The ISO 19125 standard comes in two parts. Part one, ISO 19125-1 (SFA-CA for "common architecture"), defines a model for two-dimensional simple features, with linear interpolation between vertices. The data model defined in SFA-CA is a hierarchy of classes. This part also defines representation using Well-Known Text (and Binary). Part 2 of the standard, ISO 19125-2 (SFA-SQL), defines an implementation using SQL. The OpenGIS standard(s) cover implementations in CORBA and OLE/COM as well, although these have lagged behind the SQL one and are not standardized by ISO.The ISO/IEC 13249-3 SQL/MM Spatial extends the Simple Features data model mainly with circular interpolations (e.g. circular arcs) and adds other features like coordinate transformations and methods for validating geometries as well as Geography Markup Language support.

21

Standartu dokumenti

1. ISO/IEC: ISO 19125-1:2004 Geographic information -- Simple feature access -- Part 1: Common architectureISO 19125-2:2004 Geographic information -- Simple feature access -- Part 2: SQL optionISO SQL/MM part 3

2. OpenGIS: OpenGIS Implementation Specification for Geographic information - Simple feature access - Part 1: Common architecture (05-126, 06-103r3, 06-103r4), current version 1.2.1OpenGIS Simple Feature Access - Part 2: SQL Option (99-054, 05-134, 06-104r3, 06-104r4), current version 1.2.1, formerly OpenGIS Simple Features [Implementation Specification] for SQLOpenGIS Simple Features Implementation Specification for CORBA (99-054), current version 1.0OpenGIS Simple Features Implementation Specification for OLE/COM (99-050), current version 1.1

http://www.opengis.org/GIS Standards and Interoperability (ESRI)http://www.esri.com/software/opengisGIS Standards (NCGIA Core Curriculum 1990)http://www.geog.ubc.ca/courses/klink/gis.notes/ncgia/toc.htmlInternational Organization for Standardization (ISO)http://www.iso.org/iso/home.htmSpatial Data Standards and Interoperability White Paper (ESRI)http://www.esri.com/library/whitepapers/pdfs/spatial-data-standards.pdf

22