A COMPARISON OF ROTATION-BASED METHODS FOR ITERATIVE RECONSTRUCTION ALGORITHMS

Rotation-based projectors and backprojectors offer unique trade-offs b etween accuracy, computational complexity, and smoothing, We analyzed six different rotation methods for generating projections and iterativ e reconstructions of tomographic data, Nearest neighbor, upsampled nea rest neighbor, bilinear interpolation, and bicubic interpolation were all used to determine the values at rotated grid points, A decompositi on of the rotation transformation matrix into three components was als o investigated, Linear and cubic interpolation were used in the three- pass method. For all of the methods, mean normalized square errors wer e computed, Our results demonstrate the tradeoffs associated with the different methods and suggest that the three-pass method with cubic in terpolation offers a computationally efficient approach with accuracy between that of bilinear and bicubic interpolation.