Two-stage Image Denoising by Principal Component Analysis with Local Pixel Grouping

(a) Original image Cameraman; (b)noisy image(PSNR=22.1dB);(c)denoised image after the first stage of the proposed method (PSNR=29.8dB) and(d) denoised image after these cond stage of the proposed method (PSNR=30.1dB). We see that the visual quality is much improved after these condstage refinement.