OPTICAL NEUROCHIP FOR IMAGE-PROCESSING

This paper proposes a method to realize a highspeed processing of image data utilizing the analog memory function of the optical neurochip. The result of experiment also is presented. The features of the proposed method are that the image data can directly be processed in the two-dimensional form and a large-scale problem can be processed with a high speed by utilizing the spatial parallelism of the light. In this paper, it is shown first that the variable sensitivity photodetector, which is the basic element;of the system, can function as the optical analog memory, where the value proportional to the product of the input light intensity and the control voltage is stored in the element as the light detection sensitivity and the stored value can be read by the optical signal. Then the application of the optical analog memory function to the image processing is considered. The optical neurochip is constructed by integrating the variable. sensitivity photodetector in a two-dimensional array, and it is shown that the difference of two input images can be calculated. The function is realized by selecting the polarity of the control voltage in inputting the pattern. Lastly, the image difference function is applied in the experiment for the selective detection of the moving object where the dynamic image is used as the input. In other words, the light irradiated from the moving object is used as the input pattern; and it is shown experimentally that the trajectory of the moving object is detected but the signal is not detected when the object is still.