Edge enhancement techniques for improving the performance of binary phase-only filter pattern recognition devices

Several edge enhancement techniques are examined for improving the performance of binary phase-only filter pattern recognition devices. These include the linear techniques of blocking the lower Fourier orders and Laplacian filtering as well as the nonlinear techniques of phase extraction and phase binarization. The results indicate that the nonlinear techniques outperform the linear techniques when there is no distortion caused by aperturing the input information. However, when the input is apertured, both the linear and nonlinear techniques yield approximately the same peak-to-noise ratio.

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