Browsing by Author "Fujii, H."

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    Coherent spatial-filtering with simulated input
    Fujii, H.; Almeida, S. P. (Optical Society of America, 1979-11)
    A disadvantage of a well-tuned matched filter is partly overcome in recognizing biological species, i.e., algae. A simplified input pattern is prepared which simulates a given species. The matched spatial filter for this pattern can identify various diatoms in the species with considerably less size and orientation dependence. In addition, the filter still retains a high degree of pattern discrimination against other species.
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    Fourier-transform differences and averaged similarities in diatoms
    Almeida, S. P.; Fujii, H. (Optical Society of America, 1979)
    Phase contrast photographs of diatoms are characterized from their Fourier transform taken through an optical diffractometer. The system output is placed on line to a PDP11/40 providing digital subtraction of two output spectral distributions due to different species. Differences obtained in this manner are used for characterizing various species. An average Fourier transform taken through coherent additions is also analyzed to find common features in a given set of diatoms.
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    Rotational matched spatial filter for biological pattern recognition
    Fujii, H.; Almeida, S. P.; Dowling, J. E. (Optical Society of America, 1980-06)
    Randomly oriented microbiological patterns are recognized by rotating a matched spatial filter with an optical wedge prism. The filter is made from a composite input pattern with various sized objects to cover wider ranges of size variation in a species to be identified.