Parallel line grouping in irregular curve pyramids

In order to usefully apply the concept of the curve pyramid on grouping problems, the shift variance problem must be overcome by extending the concept to irregular pyramids. These have a structure that adapts to the image data by deriving control information from curve relations. The algorithm that builds the irregular curve pyramid by deriving higher levels of abstraction from a set of relations goes far beyond merely solving the shift variance problem. It can reduce the computational complexity in comparable applications where all possible combinations of parts have to be checked in order to reassemble complex objects