Thematic filtering and scene interpretation based on complete invariant systems of features

A mixed combinatorial and analytic approach is presented for thematic filtering of simple patterns in a scene and for interpretation of how they are arranged in the form of a complex pattern. By "simple patterns" we mean basic objects like cars, trucks, or trees while a complex pattern could be an arrangement of such objects in an outdoor scene. In our procedure, the simple patterns of interest are identified by comparison with "reference simple patterns" (reference images) via comparison of features associated with local configurations in the test and reference images. The features are invariant with respect to translation, rotation, and scaling. The procedure also gives the relative positions and orientation of the simple patterns found and thus provides the required interpretation information.