Finding stable salient contours

Methods for generating maximally stable extremal regions are generalized to make intensity trees. Such trees may be computed quickly, but they are large so there is a need to select useful nodes within the tree. Methods for simplifying the tree are developed and it is shown that standard confidence tests may be applied to regions identified as parent and child nodes in the tree. These tests provide a principled way to edit the tree and hence control its size. One of the algorithms for simplifying trees is able to reduce the tree size by at least 90% while retaining important nodes. Furthermore the tree can be parsed to identify salient contours which are presented as generalisations of maximally stable extremal regions.