Abstract: A method of X-ray computerized tomography whereby a scanner in which an X-ray source for irradiating an X-ray in a cone-beam shape to an object and a two-dimensional detector for detecting the X-ray transmitted through the object are installed is rotated around the object and a projection angle is changed and a distribution of X-ray attenuation coefficients of the object is reconstructed from the transmitted X-ray images obtained at a plurality of projection angles.
Abstract: A typical nuclear well logging tool forms a count rate data stream including statistical noise. A robust single pass partially deconvolved smoothing filter matched to the tool response is applied to the count rate data to enhance vertical resolution while minimizing the statistical noise increase. The smoothing filter is partially deconvolved by the application of a three point deconvolution characteristic of the cusp portion of a related cusp function and a box function representative of the tool response.
Type:
Grant
Filed:
September 26, 1994
Date of Patent:
September 30, 1997
Assignee:
Halliburton Logging Services, Inc.
Inventors:
Larry L. Gadeken, Larry A. Jacobson, Gulamabbas A. Merchant
Abstract: An x-ray CT scanner acquires projection profiles P during a scan which are corrected for errors caused by non-uniform response of the detectors along the z-axis. In addition to corrections using a calibration vector Q that offsets errors caused by variations in the detector response, additional corrections are made to offset object dependent errors caused by the same variations in detector response when imaging certain objects.
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