Fast image reconstruction for cone-beam ART based on minimal reconstruction region

To solve the slow reconstruction speed problem of cone-beam algebraic reconstruction technique (ART) algorithm, considering the characteristic of large difference of reconstruction objects of industrial computed tomography (CT) in size, a fast image reconstruction method based on minimal reconstruction region is proposed. The envelope of minimal region is constructed by cone-beam projection of different views. The envelope of minimal region is expanded to eliminate the artifact which exists near the boundary of reconstruction object. On this basis, the computation of vowel index and weight coefficient of ray traversing through the minimal reconstruction region is presented. The method can adaptively determine the minimal reconstruction region according to the size of reconstruction object, thus unnecessary computation is reduced farthest. Experimental results show that the proposed method can not only improve the reconstruction speed of ART greatly but also improve the reconstruction quality effectively.