We present a method for automatically solving apictorial jigsaw puzzles that is based on an extension of the method of differential invariant signatures. Our algorithms are designed to solve challenging puzzles, without having to impose any restrictive assumptions on the shape of the puzzle, the shapes of the individual pieces, or their intrinsic arrangement. As a demonstration, the method was successfully used to solve two commercially available puzzles. Finally we perform some preliminary investigations into scalability of the algorithm for even larger puzzles.

A refinement of the method of differential invariant signatures for object recognition is presented. The value of the method lies in its compromise between local and global identifying properties, thereby allowing us to distinguish non-congruent curves whose Euclidean signatures have identical trace.