Impulse noise removal by a global–local noise detector and adaptive median filter

Noise detection-based median filters have been widely adopted to reduce impulse noise. However, the number of misclassified pixels is obviously increased at high noise density. In order to overcome this drawback, a global–local noise detector is proposed in this paper. Based on the noise detection, an adaptive median algorithm is presented. Simulation results show that the new filter can effectively reduce impulse noise and preserve more details of original images.