Fast Paralleled Removal Method of Impulsive Noise Using Edge Strength
Yusuke Koshimura, Takashi Miyazaki, Yasuki Yokoyama, Yasushi Amari, Hiroaki Yamamoto · 2018
The Median Filter is known as a method for effectively removing to impulsive noise. However, this method occurs deteriorating image quality since the filtering process is also applied to non-noise pixels. Therefore, a method called the Switching Median Filter, improved capable of distinguishing between noise pixels and non-noise pixels has been proposed. Our Multi-directional Switching Median Filter is one of which has been improved such as same. As the first step in this method, the detection and removal processing of pixels considered as noise are performed by using a 2x2 detection operator from four detections. As the second step, each density value of the noise pixel is corrected to restore the image by averaging process. However, this method as same as other methods takes time to remove noises in the high resolution image. Also, it requires an optimal threshold in order to make the image quality better for each image. In this paper, we propose a novel method that is parallelized to improve processing speed by allocating pixels of this MSMF to the threads of GPU, and whose threshold value is calculated according to the average value of edge strength around the target pixel. And we report the effective performance of image denoising for the difference in image noise ratio compared some conventional methods.