| 摘要 |
The specification concerns a method and apparatus for tomographically imaging different selected planes of a three-dimensional object by detecting radiation through a coded aperture mask, storing an image of the radiation detected over a period of time, and decoding each selected object plane by a correlation process appropriate to the size of the shadow of the mask cast on the detector by points in the selected object plane. Each object plane to be imaged is selected by adjusting one or both of the object/detector and mask/detector separations D and d respectively so that D/d is a constant for all selected object planes. This provides a fixed shadow size of the mask on the detector for all selected object planes, and thus permits the use of a fixed decoding process. In the preferred embodiment the mask is a mosaicked mask based on m-sequences, and the decoding process is implemented in hardware and uses a Fast Hadamard Transform.
|
