Scientists, engineers, and analysts are confronted with ever larger and more complex sets of data, whose analysis poses special challenges. In many situations it is necessary to compare two or more datasets. Hence there is a need for comparative visualization tools to help analyse differences or similarities among datasets.

Well-established techniques for comparing images frequently place them side-by-side. A major drawback of such approaches is that they do not scale well. Other image comparison methods encode differences in images by abstract parameters like color. In this case information about the underlying image data gets lost.

We present VAICo - Visual Analysis for Image Comparison. This new method for visualizing differences and similarities in large sets of images preserves contextual information, but also allows the detailed analysis of subtle variations. Our approach identifies local changes and applies cluster analysis techniques to embed them in a hierarchy. The results of this process are then presented in an interactive web application, which allows users to rapidly explore the space of differences and drill-down on particular features.

The approach was presented at VAST 2013, further information can be found here.
Johanna Schmidt, M. Eduard Gröller and Stefan Bruckner: VAICo - Visual Analysis for Image Comparison. IEEE Transactions on Visualization and Computer Graphics 19(12), December 2013, pp. 2090-2099, IEEE Educational Activities Department, Piscataway, NJ, USA

You can test our approach online with the following datasets:
Dataset Puzzle
. . .
Dataset Satellite
. . .
Dataset Segmentation
. . .

If you would like to apply VAICo to your own data, do not hesitate to contact us!