Removal of impulse noise from highly corrupted images by using noise position information and directional information of image

In this paper, a new progressive switching type filter is proposed in order to restore images corrupted by salt-pepper impulse noise. The algorithm consists of two main processes: 1) noise detection - an impulse detection algorithm is used before filtering, a noise position image is obtained and 2) noise filtering - disturbed pixels are only filtered by using the noise position image. In this paper, we study the second process (i.e., noise filtering). In the past, the median filter is used for the second process. In this paper, we introduce a weighted average (WA) filter into second process. Using the directional property of input images derives the weights of the WA filter. Therefore, better restoration results are expected. Simulation results demonstrate that the proposed method is superior to the conventional filters which is used the median filter in the second process.