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Symmetrical Fourth-Order Partial Differential Equation De-Noise for THz Pulse Imaging

Over past several years, there has been a significant interest in employing terahertz (THz) imaging technology. Due to low contrast and bit noise in scanning THz pulse imaging, a novel fourth-order partial differential equation (PDE) denosing algorithm is proposed in this paper. The proposed approach is capable of overcoming THz pulse image block suppressing noise and preserving the sharp edges at the same time. A symmetric discrete algorithm based on four-neighbor system is developed to solve the new model. Median filtering is applied to alleviate the speckle effects in the processed image at last. Experimental results are provided to show that the proposed approach outperforms the image denoising approaches developed in the literature, which is useful for further image processing and recognition.