Several general approaches are possible for determining thresholds for change detection. First the signal, noise, or both can be modelled. Second, either their intensity and/or spatial properties can be modelled. In [14] we consider all of the four combinations of pairs of object and property (signal/noise and intensity/spatial distribution) and describe four techniques for threshold determination that fall into each of these categories (see table 1). Note that most standard intensity image thresholding techniques belong to the signal/intensity class. Here we will just describe the two spatial methods listed in the bottom row.
Table 1: Techniques for threshold selection described in this paper