| 摘要 |
Standard mosaic geometries in modern imaging systems, such as a thermal imager, give rise to the fundamental limitation of creating undersampled images that are degraded by aliasing which is a distortion affecting spatial frequency components of the image that are higher than half the sampling frequency. A point target image can either cover one image sensing element and generate a strong single signal or cover up to four adjacent sensing elements which will produce much weaker signals and result in edges of a spread target being degraded by spurious registration. In order to minimize aliasing for a square sampling grid, improved geometries for the detector elements are used which reduce the number of dead zones associated with the current square geometries for the detector elements. One type of geometry for a detector element is a robigon having the form of a polygon obtained by substituting linear sides of a square by a triangular wave shaped edge. This new shape of detector element has the same area as the original square but when closely interfitted with its neighbours forms a mosaic in which all dead zones between the elements are broken into non-linear strips. Similar results are obtained when a sine wave, rather than a triangular wave, shaped side is used to break the normal dead zones that exist between square shaped image sensing elements.
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