<title>Method for recognizing multiple radiation fields in computed radiography</title>

An algorithm is developed to detect collimation regions in computed radiography images. Based on a priori knowledge of the collimation process, the algorithm consists of four major stages of operations: (1) pixel-level detection and classification of collimation boundary transition pixels; (2) line-level delineation of candidate collimation blades; (3) estimation of the most likely partitioning; and (4) region- level determination of the collimation configuration. This algorithm has been tested on a set of 8,436 images, which includes 7,703 single-exposure images and 733 multiple- exposure images. An overall success rate in excess of 99% has been achieved.