Removal Of Random-valued Impulse Noise From Images

Median filters have been widely used for removing impulse noise, since median filters are quite effective for the noise removal. The median filtering method and its improved methods are an effectual approach to remove random-value impulse noise in images. However, most methods have the same shortcomings, those are, finding the optimal threshold is difficult and the edges and textures structure of images are over-smoothed. In the paper, it proposes a novel method based on detail image filtering using structure windows to remove random-value impulse noise from images. First, the histogram of a noisy image is used to estimate the noise ratio. Next, it filters the detail image using structure windows, and then it uses the histogram of the result and the noise ratio to determine the threshold adaptively. Finally, the result of the median filtering is modified using the modify image which obtained from the detail image. The simulation results show that the proposed method can remove impulse noise meantime preserve the detail structure of the image. It is superior to the existing methods in performance.