Parallel connected-Component-Labeling based on homotopy trees

Abstract

Taking advantage of the topological and isotopic properties of binary digital images, we present here anew algorithm for connected component labeling (CLL). A local-to-global treatment of the topologicalinformation within the image, allows us to develop an inherent parallel approach. The time complexityorder for an image of m ×n pixels, under the assumption that a processing element exists for each pixel, is near O (log(m + n )) . Additionally, our method computes both the foreground and background CCL, and allows a straightforward computation of topological features like Adjacency Trees. Experiments show thatour method obtains better performance metrics than other approaches. Our work aims at generating anew class of labeling algorithms: those centered in fully parallel approaches based on computationaltopology, thus allowing a perfect concurrent execution in multiple threads and preventing the use ofcritical sections and atomic instructions.