Generalizing Simultaneously to Support Smooth Zooming: Case Study of Merging Area Objects

When users zoom in or out on a digital map, the map should change correspondingly to present geographical information at proper levels. A way to help map users better keep track of their interested objects is to change the map smoothly instead of discretely switching between several levels of detail. This paper focuses on the problem of...

Finding Optimal Sequences for Area Aggregation-A* vs. Integer Linear Programming

To provide users with maps of different scales and to allow them to zoom in and out without losing context, automatic methods for map generalization are needed. We approach this problem for land-cover maps. Given two land-cover maps at two different scales, we want to find a sequence of small incremental changes that gradually transforms one...

Paralleling generalization operations to support smooth zooming: case study of merging area objects

When users zoom out on a digital map, some area objects become too tiny to be seen, resulting in visual clutters. To avoid this problem, the relatively unimportant areas should be merged with their neighbors to form larger<br/>areas. In order to provide small and smooth changes so that users can easily keep their contexts, we merge a pair of...

Multi-layer vario-scale web map comparer with dynamic transitions and visual analytical tool

This paper presents a web map juxtaposition comparer. Using the comparer, we can place two maps side by side for comparison. The maps of the comparer can contain multiple layers, and each of them can be a multi-scale layer<br/>or a vario-scale layer. We enhance the comparer’s visual analytical ability by developing more functionalities,...