| 摘要 |
PURPOSE:To effectively compress projection data, and to attain high compression ratio, and simultaneously, to restore a high quality picture by providing a reconstituting part consisting of a redundancy realizing means and a reconstituting means, and a compression restoring part consisting of an encoding means, etc. CONSTITUTION:In a course that the projection data of a body P to be inspected from many directions are collected by an X-ray CT scanner of an external device 1 and fetched in the reconstituting part 5, and a two-dimensional picture is reconstituted, the essential redundancy of the projection data is realized. Namely, the projection data is orthogonal-polynominal-series-developed by the redundancy realizing means 7, and thus, the essential redundancy of the projection data is realized. The processed result of the means 7 is sent to the encoding means 8 and encoded, and the redundancy of the projection data is deleted by this encoding. Then, the restoration of compressed data is performed by a decoding means 10, and the result of it is fetched in the reconstituting means 11, and here, the two-dimensional picture is reconstituted. Thus, the effective compression of the projection data becomes possible, and the high compression ratio is attained, and simultaneously, the high quality picture can be restored. |
