Improved DCT-Based Nonlocal Means Filter for MR Images Denoising

Figure 5

Influence of subspace’s dimensional number 𝑑 for the denoising effect. 𝑆 is fixed to 11, 𝑟 is fixed to 5, and ℎ is set to get the best PSNR. (a) The experiments are performed on T1-weighted images; (b) the experiments are performed on T2-weighted image; (c) the experiments are performed on PD-weighted image.

(a) Influence of DCT subspace dimensionality 𝑑 on T1-weighted image

(b) Influence of DCT subspace dimensionality 𝑑 on T2-weighted image

(c) Influence of DCT subspace dimensionality 𝑑 on PD-weighted image