Anisotropic Diffusion for Preservation of Line-edges

In existing approaches, diffusion is performed in four directions (North, South, East, West) without specific conditions. Therefore, these methods have shortcomings of distorted with the existence of impulse noises. In this paper, a new anisotropic diffusion based on directions of line-edges is proposed to enhance preservation of line-edges together with removal of noises. In the proposed method, an edge detection mask is used to find the direction of a line-edge. As a result, when the magnitude of edge detection is large enough, there exists a line-edge. In the case of a line-edge, the weight of diffusion is selected adaptively according to the direction of the line-edge. The diffusion is based on 8-directions diffusion with emphasis on the line-edge direction. Experimental results show that the proposed method can eliminate noise while preserving contour of line-edges.