We present a framework for categorical shape recognition. The coarse shape of an object is
captured by a multiscale blob decomposition, representing the compact and elongated parts
of an object at appropriate scales. These parts, in turn, map to nodes in a directed acyclic
graph, in which edges encode both semantic relations (parent/child) as well as geometric
relations. Given two image descriptions, each represented as a directed acyclic graph, we
draw on spectral graph theory to derive a new algorithm for computing node …