Tile-based information systems

Nguyễn Hải Châu

Bộ môn Các hệ thống thông tin

Khoa CNTT - ĐHCN

Web-based mapping applications

Mid-1990s: Yahoo maps, MapQuest, Microsoft’s TerraServer Slow rendering Unfriendly user interface

2005: Google Maps Slippy maps, using HTML and JavaScript Quickly move and zoom Technology: Tiled images

2013: Google maps, Bing maps, Yahoo maps, Nokia’s Here maps, OpenStreetMap

Properties of tile-based mapping systems

Map view: Multiple discrete zoom level Multiple image tiles use to visualize a

single map view Image tiles are accessible using an

addressing scheme Tiled images are stored on a server and

are pre-processed

Mapping Earth: spherical to 2D

Mapping Earth to gridded surface

Global logical tile scheme

Level 1 (i=1) Rows = 2i-1, cols = 2i

Global logical tile scheme

Level 2

Degree per pixel (DPP) For a given pixel dimension:

where p = number of pixel per tile, i = zoom level

pDPPi2

0.360

DPP of map levels

Open source mapping solutions

Server-side: MapServer Client-side: OpenLayers Server+Client solutions: GeoMajas,

GeoMoose, MapBender, MapFish, MapGuide

Reference: http://www.osgeo.org

Textbook

John T. Sample, E. Ioup, Tile-based geospatial information systems: Principles and practices, Springer, 2010.

Chapters to read Chapter 3: Tiled mapping clients (W3) Chapter 5: Image tile creation (W5) Chapter 6: Optimization of tile creation

(W5) Chapter 7: Tile storage (W7) Chapter 8: Practical tile storage (W7) Chapter 9: Tile serving (W9) Chapter 11: Tile creation using vector

data (W11) Reference: Chapter 10 – Map projection

Requests

Read the listed chapters Investigate one of the following

package: GeoMajas, GeoMoose, MapBender, MapFish, MapGuide and mapping their real solution to the chapters you have read

Requests

Reorganize what you read, investigated and write as a technical report less than 20 A4 pages

Use vector data downloaded from OpenStreetMap as input for your tile-based map solutions to run your own demonstration

Grading

Report Solution demonstration Presentation

Software demonstration

OSGeo Live: http://live.osgeo.org More information:

http://www.osgeo.org