Skip to main content

Carlea Holl-Jensen||


Zhao, H., Shneiderman, B. (December 2002)
Colour-Coded Pixel-Based Highly Interactive Web Mapping for Georeferenced Data Exploration
International Journal of Georgraphical Information Science, 19, 4, 2005.
HCIL-2002-26, CS-TR-4431, UMIACS-TR-2003-02, ISR-TR-2005-35

This paper describes an image-based technique that enables highly interactive Web choropleth maps for geo-referenced data publishing and visual exploration. Geographic knowledge is encoded into raster images and delivered to the client, instead of in vector formats. Differing from traditional raster-image-based approaches that are static and allow very little user interaction, it allows varieties of sub-second fine-grained interface controls such as dynamic query, dynamic classification, geographic object data identification, user setting adjusting, as well as turning on/off layers, panning and zooming, with no or minimum server support. Compared to Web GIS approaches that are based on vector geographic data, this technique has the features of short initial download time, near-constant performance scalability for larger numbers of geographic objects, and download-map-segment-only-when-necessary which potentially reduces the overall data transfer over the network. As a result, it accommodates general public users with slow modem network connections and low-end machines, as well as users with fast T-1 connections and fast machines. The client-side (browser) is implemented as light-weight Java applets. YMap, an easy-to-use, user-task-oriented highly interactive mapping tool prototype for visual geo-referenced data exploration is implemented using this technique. Keywords: Web GIS, choropleth map, information visualization, dynamic query, universal usability Web supplement:


Keshif:  Simplicity Driven Visual Faceted Browser Screenshot

Keshif: Simplicity Driven Visual Faceted Browser
More information

Tech Reports
Video Reports
Annual Symposium

Seminars + Events
HCIL Seminar Series
Annual Symposium
HCIL Service Grants
Events Archives
HCIL Conference Travel Award
Job Openings
For the Press
HCIL Overview
Become a Member
Collaborating Groups + People
Academic Visitors
Join our Mailing List
Contact Us
Visit Us
HCIL Store
Give the HCIL a Hand
HCIL T-shirts for Sale
Our Lighter Side
HCIL Memories Page
Faculty/ Staff
Ph.D. Alumni
Past Members
Research Areas
Design Process
Digital Libraries
Physical Devices
Public Access
Research Histories
Faculty Listed by Research
Project Highlights
Project Screenshots
Publications and TRs
Studying HCI
Masters in HCI
PhD in HCI
Visiting Scholars
Class Websites
Sponsor our Research
Sponsor our Annual Symposium
Active Sponsorship
Industrial Visitors