| 摘要 |
1,202,937. Spatial filters. INTERNATIONAL BUSINESS MACHINES CORP. Sept.25, 1967 [Oct.18, 1966], No.43466/67. Heading G2J. A code translation filter, for generating a given image defined by function v from a given object defined by function u when illuminated by coherent collimated light, is made from a plurality of rectangular cells each of width w and height h, (w and h being submultiples of the width and height respectively of the filter) evaluating the Fourier transforms of the functions v, u, respectively at each cell and thus obtaining the modulus and phase of the filter function desired for each cell and arranging areas of different transparency in each cell the area dimensions and their relative positions in the cell being so chosen that the evaluated filter function is satisfied. As described each cell has a transparent area of width equal to half that of the cell and a height varying according to the evaluated modulus of the filter function, the transparent area having its centre line spaced from that of the cell by a distance varying according to the evaluated phase of the filter function for that cell. |
