Abstract: Equipment and methods improving the quality of a tomograph are presented for rearranging divergent beam derived data into parallel data. The equipment and method perform uniform noise distribution interpolation either in the reordering phase or in the rebinning phase or in both phases. When the uniform noise distribution interpolation is employed noise streak artifacts, normally present in images, virtually disappear.

Abstract: A system and method are presented for reprojecting images generated by a back-projector. The image data is processed to distinguish hard and soft tissue and then is transmitted to the normal input of the back-projector. Pseudo-projections (reprojections) are obtained at the normal output of the back-projector. Each image row is fed into the input of the back-projector as a normal projection. The "image" generated by the back-projector is now one projection. In order to generate the required amount of reprojections "L", the image is supplied to the back-projector "L" times. Each time the image is presented with constants, such as the reprojection angle associated with the specific reprojection. The reprojections at the back-projector output are combined in a feed-back circuit with the original projections to correct for artifacts, such as polychromatic artifacts.