Publication Type
Conference Paper
Book Title
Spatial Gems Volume 2
Publication Date
Page Numbers
107 to 120
Volume
2
Publisher Location
New York, New York, United States of America
Conference Name
The 4th ACM SIGSPATIAL International Workshop on Spatial Gems (SpatialGems 2022). November 01, 2022. Seattle, Washington, USA.
Conference Location
Seattle, Washington, United States of America
Conference Sponsor
ACM
Conference Date
-
Abstract
Heatmap is a common geovisualization method that interpolates and visualizes a set of point observations on a map surface. Most of online web mapping libraries implement a one-pass heatmap algorithm using HTML5 canvas or WebGL for efficient heatmap generation. However, such implementation applies additive operations that accumulate the rendering of point weights on the map surface grid, making it inappropriate for visualizations that require the highlighting of both low and high weights. We introduce \textit{hilomap}, an online heatmap algorithm that highlights surface areas where points with both low and high trends are located. An HTML5 Canvas-based reference implementation on OpenLayers is presented and evaluated.