Fig. 4

Test trials for filtering grayscale images. Left column - image “clock;” right column - image “Lena.” First row - 80 % of impulses (a, d); second row - 90 % of impulses (b, e); third row - 95 % of impulses (c, f). For each image and noise percentage: upper left corner - corrupted image; upper right corner - filtered with decision-based/adaptive median filter; lower left corner - after single iteration with BM3D; lower right corner - after five iterations with BM3D