| 摘要 |
<p>A method of generating images of a specimen containing at least two regions of different opacity to the passage of radiation comprises irradiating the specimen with radiation from a radiation source, detecting the radiation to produce a plurality of signals indicative of the amplitude of the radiation passing through the specimen in a corresponding plurality of different directions and processing the signals to derive further signals indicative of contours of maximum local discontinuity in opacity or texture thereby providing an indication of the position of the three-dimensional boundary surface between said two regions.</p> |
