| 摘要 |
PURPOSE:To attain high speed processing, by performing a simple filtering operation in place of conventional packing and filtering operations, in a filter operting device used for an X-ray CT device. CONSTITUTION:Projection data at each view obtained by rotating an X-ray generator 2 and a detector groups 3 sequentially to a body 4 to be inspected, are amplified, integrated and AD-converted with a data logger 6 and stored as digital data. Pre-processing is caried out for the data at a pre-processing device 7, led to a compression FFT(discrete high speed Fourier transformation) device 8 for the processing according to equation I . The filtering operation processing of a specific equation is carried out at a filter device 9, and a compression inverting Fourier transformation is performed at a compression inverting FFT device 10. Further, in the FFT operation, the composite FFT operation of N/2 points is preformed based on input data pairs of N/2-point, f0+jf1, f2+jf3, -, fN-2+jfN-1. |
