Method of hierarchical backprojection fast image

摘要

(57) A method for performing a back projection tomographic image to (12) from (10) [Abstract] sinogram, sub-sinograms of each (14, 16, 18, 20) the image size of one pixel Up to express, in which recursively, comprises the step of re-divided into (14, 16, 18, 20) sub-sinograms multiple sinogram (10), preferably. Each sub-sinogram final (14, 16, 18, 20), is back-projected to produce the (22, 24) sub-image corresponding to the plurality of the sub-images (22, 24 , 26, 28) are integrated to generate an image. Two algorithms can be used for decomposition. High precision With the exact decomposition algorithm, but is relatively slow. Approximate decomposition algorithm is a fast as low accuracy. By switching algorithms two degradation precision is realized in a short time, the process of back projection is much faster.