1
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).
2
Attēls jāpielāgo lietošanai datorā
3
Computer graphics are graphics created using
computers and more generally, the representation and
manipulation of graphics data by a computer.
Glabāšana
(storage)
Relāciju DBS
Relacijuobjektu DBS
XML DBS
Sameklēšana
un izgūšana
(search and
extraction)
Vizualizācija
(visualization)
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
4
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).
5
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.
6
Datorizētā ražošana (coputer aided manufacturing
(CAM))
Ir datoru lietošana ražošanā, piemēram, tehnoloģisko procesu vadībā,
materiālu uzskaites un sadales, operatīvās plānošanas u. c. darbu
automatizācijā.
7
CAD/CAM sistēmas un apakšsistēmas
8
a) projektēšana (design)
b) izstrāde (manufacturing)
9
Ģeogrāfija un ģeometrija
10
Locations on the Earth’s surface is usually marked using the longitude and
latitude.
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.
11
GIS sistēmas
12
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.
13
Datorgrafika pētniecības sistēmās
14
15
16
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.
17
Skaitļošanas ģeometrijas problēmas
1. Ģeometrijas objekti kā diskrētas vienības (geometric objects as
discrete entities)
Problēma: nepārtrauktā telpa (reālā dzīve) un diskrētā telpa (datori)
-----------------------------------------------------------------------------------------------------------
18
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.
19
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.
20
Rastra grafika
Vektoru grafika (objekti un
telpa)
21
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.
22
Standartu dokumenti
1. ISO/IEC:
ISO 19125-1:2004 Geographic information -- Simple feature access -- Part
1: Common architecture
ISO 19125-2:2004 Geographic information -- Simple feature access -- Part
2: SQL option
ISO 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 1.2.1
OpenGIS 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 SQL
OpenGIS Simple Features Implementation Specification for CORBA (99054), current version 1.0
OpenGIS 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/opengis
GIS Standards (NCGIA Core Curriculum 1990)
http://www.geog.ubc.ca/courses/klink/gis.notes/ncgia/toc.html
International Organization for Standardization (ISO)
http://www.iso.org/iso/home.htm
Spatial Data Standards and Interoperability White Paper (ESRI)
http://www.esri.com/library/whitepapers/pdfs/spatial-data-standards.pdf