Table 6. Grand average PSNR (dB) of estimated denoised images under zero-mean additive Gaussian noise exploiting patch-based sparse and redundant representations.

σ	OMP	GOMP	CMP	Cauchy	Fair	Huber	Tukey	Welsch
5	36.33	36.31	35.62	36.56	36.55	36.52	36.20	36.29
10	32.38	32.36	31.01	32.44	32.22	32.39	32.17	32.17
15	30.35	30.33	28.95	30.25	29.88	30.21	30.01	29.97
20	28.97	28.96	27.85	28.78	28.40	28.76	28.58	28.53
25	27.93	27.92	27.12	27.70	27.39	27.70	27.55	27.51