On-board optical joint transform correlator for real-time road sign recognition

摘要

We design, implement, and test an on-board optical joint transform correlator, using a nonlinear optically addressed ferroelectric liquid-crystal spatial light modulator in the Fourier plane. This compact correlator performs real-time and on-board recognition tasks, such as road sign recognition. The influence of the nonlinearity in the Fourier plane is investigated, and scale-invariant filters are tested and implemented. Preliminary results from real-time dynamic scenario experiments are presented. Electronic and optical pre- and postprocessing as well as the extension to silicon backplane devices are discussed.