Fig. 1. Structure diagram of optical convolution system

Fig. 2. Diagram of window division

Fig. 3. (a) The distribution of input signal feed to P₂; (b) The shape and value of kernel which set in P₂

Fig. 4. Ray marking

Fig. 5. Simulate the optical path

Fig. 6. (a) Gaussian operator; (b) Variant of Prewitt operator; (c) Prewitt's gradient along the x direction; (d) The image gradient obtained by the improved operator along thexdirection

Fig. 7. Diagram of optical convolution neural network

Fig. 8. Pre-processing result of valid convolution with stride 1