Iterative Adaptive Unsymmetric Trimmed Shock Filter for High-Density Salt-and-Pepper Noise Removal

In this paper, an iterative adaptive unsymmetric trimmed shock filter based on partial differential equations (PDE) is proposed to remove high-density salt-and-pepper noise by preserving the edge details in the images. This algorithm consists of two steps: identification of pixels affected by the salt-and-pepper noise and recovery of these noisy pixels using adaptive unsymmetric trimmed shock filter. Shock filter has been used in image processing literature for image restoration and enhancement task. However, its use was limited to unwanted noise removal, enhancement, despeckling, etc. In the proposed work, a modified form of shock filter termed as adaptive unsymmetric trimmed shock filter is designed to remove the salt-and-pepper noise. The proposed algorithm is tested with different test images. Three performance evaluation measures: PSNR, CR and MSSIM are used to validate the proposed scheme. The performance of the proposed algorithm claims better results than the other considered eight existing state-of-the-art techniques.