earticle

영어

Aiming at the impulse noise generated in capturing the images of insulator on power lines, a denoising method based on peer groups is proposed. The center pixel variance σcenter
is defined, the minimum of neighborhood variance and center σmin is treated as threshold
σmin and the peer group is determined by comparing the relation between absolute value of gray value difference and σmin . According to the size of peer group and its complement set, center pixel is estimated when noisy pixels exist in the neighborhood window. Otherwise, the size of window is adjusted adaptively and center pixel is estimated on the basis of mean value of non-noisy pixels within adjusted window. The experimental results show that the method can get a higher peak signal to noise ratio, IEF and SSIM when there is high density impulse noise in an image.