For many tasks of automated visual inspection and environmental perception, acquisition and evaluation of a single image is not sufficient. The reason is that the information of interest cannot be acquired from a single image at all or with the necessary quality. This insufficiency can result from sensor characteristics such as sensor noise. In addition, the information of interest may be unavailable by direct observation. In such cases, the desired information can often be obtained by recording multiple images (so-called image series), which are then combined in an image fusion in order to achieve a new or improved representation of the image content or the scene properties.
This tutorial gives an introduction to common fusion approaches for image data and illustrates main aspects of image fusion. Image sensors are characterized with respect to the fusability of the acquired data. Abstraction levels on which an image fusion can be performed are explained. To describe processing stages for image fusion in general, a universal fusion scheme is introduced. The mentioned aspects of image fusion are illustrated by means of practical examples.