A pyramidal algorithm for area morphology

A fast algorithm that approximates area morphological filters is presented. Area morphological filters enable the elimination of connected components within image level sets according to area alone. To date, area morphological filters have been limited in application due to the high computational expense involved with connected component analysis. The pyramidal implementation described here dramatically reduces the computational cost by simultaneously creating a marker image and performing reconstruction in a coarse-to-fine manner. The pyramidal algorithm reduces the computational cost by three orders of magnitude for standard-sized grayscale images. Image examples and an analysis of the computational expense are provided in the paper.