Table 2 PSNR and SSIM of the compared methods for different MRI modalities and Rician noise levels

T1w

PSNR

NLM

36.74

31.07

29.27

28.03

26.86

25.72

24.63

23.46

G-NLM

36.23

32.11

29.16

28.93

27.34

27.01

25.85

24.37

BM3D

43.40

36.65

33.48

31.26

29.26

27.47

25.97

24.40

G-BM3D

42.56

36.78

33.32

32.23

30.67

29.26

26.78

26.12

SSIM

NLM

0.9700

0.9042

0.8666

0.8319

0.7968

0.7617

0.7275

0.6907

G-NLM

0.9625

0.9041

0.8745

0.8437

0.8052

0.7861

0.7432

0.7231

BM3D

0.9904

0.9632

0.9320

0.8993

0.8661

0.8326

0.8029

0.7697

G-BM3D

0.9903

0.9638

0.9362

0.9016

0.8795

0.8563

0.8247

0.7968

T2w

PSNR

NLM

33.37

27.52

24.43

22.99

22.16

21.55

20.99

20.42

G-NLM

33.43

27.51

25.12

23.37

22.06

21.87

21,34

20.64

BM3D

42.54

34.97

31.68

29.50

27.77

26.34

24.87

23.50

G-BM3D

42.89

33.67

32.54

30.68

28.52

26.43

25.26

24.37

SSIM

NLM

0.9677

0.9051

0.8637

0.8259

0.7850

0.7467

0.7078

0.6731

G-NLM

0.9658

0.9037

0.8764

0.8347

0.7938

0.7637

0.7286

0.7031

BM3D

0.9898

0.9627

0.9334

0.9084

0.8768

0.8497

0.8201

0.7918

G-BM3D

0.9884

0.9638

0.9467

0.9128

0.8856

0.8643

0.8432

0.8169

PDw

PSNR

NLM

34.81

30.11

27.55

25.85

24.74

23.95

23.35

22.75

G-NLM

36.78

32.22

29.53

26.84

24.97

24.65

24.36

23.77

BM3D

43.43

36.40

33.28

31.27

29.62

28.25

27.10

25.86

G-BM3D

43.56

37.37

34.56

32.78

30.62

30.17

28.96

26.77

SSIM

NLM

0.9728

0.9075

0.8401

0.7856

0.7435

0.7088

0.6742

0.6463

G-NLM

0.9823

0.9234

0.8564

0.7958

0.7736

0.7297

0.7056

0.6573

BM3D

0.9915

0.9665

0.9403

0.9144

0.8885

0.8678

0.8406

0.8163

G-BM3D

0.9927

0.9711

0.9568

0.9347

0.8982

0.8768

0.8543

0.8256