Openings-by-reconstruction are the oldest connected filters, and indeed, reconstruction methodology lies at the heart of many connected operators such as levelings. Starting out from the basic reconstruction principle of iterated geodesic dilations, extensions such as the use of reconstruction criteria, which constrain the reconstruction process, are discussed. The latter prevent linking distinct objects connected by narrow bridges during the reconstruction process, whilst maintaining as much edge preservation as possible. A far faster variant of filtering with reconstruction criteria is presented, which can be implemented in an O(N) algorithm in stead of O(N2 ).
Michael H. F. Wilkinson