Figure 1.
Local plane-inclination diagram.
Figure 1.
Local plane-inclination diagram.
Figure 2.
Multi-directional LPIA diagram.
Figure 2.
Multi-directional LPIA diagram.
Figure 3.
Schematic diagram of cube similarity based on MDLPIA.
Figure 3.
Schematic diagram of cube similarity based on MDLPIA.
Figure 4.
The specific flow chart of proposed filter.
Figure 4.
The specific flow chart of proposed filter.
Figure 5.
(a) Added single-look speckled image (the mean is 1 and the variance is 0.1), (b) GF-3 SAR image, (c) TerraSAR-X SAR image, (d) RadarSAT-2 SAR image, and (e) ALOS-2 SAR image.
Figure 5.
(a) Added single-look speckled image (the mean is 1 and the variance is 0.1), (b) GF-3 SAR image, (c) TerraSAR-X SAR image, (d) RadarSAT-2 SAR image, and (e) ALOS-2 SAR image.
Figure 6.
(a1) Added single-look speckle image (the mean is 1 and the variance is 0.1). Images were filtered using (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 6.
(a1) Added single-look speckle image (the mean is 1 and the variance is 0.1). Images were filtered using (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 7.
(a) Simulated true speckle noise. Ratio images between noisy and filtered images using (b) DPAD, (c) EnLee, (d) SAR-BM3-D, (e) FANS, (f) PPB, (g) DnCNN, (h) NL-means, and (i) MDLPIA-NLM filters.
Figure 7.
(a) Simulated true speckle noise. Ratio images between noisy and filtered images using (b) DPAD, (c) EnLee, (d) SAR-BM3-D, (e) FANS, (f) PPB, (g) DnCNN, (h) NL-means, and (i) MDLPIA-NLM filters.
Figure 8.
(a1) GF-3 original image. Images were filtered using (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 8.
(a1) GF-3 original image. Images were filtered using (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 9.
Ratio images between noisy and filtered GF-3 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 9.
Ratio images between noisy and filtered GF-3 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 10.
(a1) TerraSAR-X original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 10.
(a1) TerraSAR-X original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 11.
Ratio images between noisy and filtered TerraSAR-X SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 11.
Ratio images between noisy and filtered TerraSAR-X SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 12.
(a1) RadarSAT-2 original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 12.
(a1) RadarSAT-2 original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 13.
Ratio images between noisy and filtered RadarSAT-2 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 13.
Ratio images between noisy and filtered RadarSAT-2 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 14.
(a1) ALOS-2 original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 14.
(a1) ALOS-2 original image. Images filtered by (b1) DPAD, (c1) EnLee, (d1) SAR-BM3-D, (e1) FANS, (f1) PPB, (g1) DnCNN, (h1) NL-means, and (i1) MDLPIA-NLM filters. (a2–i2) Locally enlarged images of region 1 of (a1–i1), respectively. The red box and circle are areas for further observation.
Figure 15.
Ratio images between noisy and filtered ALOS-2 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Figure 15.
Ratio images between noisy and filtered ALOS-2 SAR images using (a) DPAD, (b) EnLee, (c) SAR-BM3-D, (d) FANS, (e) PPB, (f) DnCNN, (g) NL-means, and (h) MDLPIA-NLM filters.
Table 1.
Real SAR image parameters.
Table 1.
Real SAR image parameters.
Sensors | Bands | Resolution | Polarization | Number of Looks |
---|
GF-3 | C | 3 | VV | Single |
TerraSAR-X | X | 3 | HH | Single |
RadarSAT-2 | C | 8 | HV | Single |
ALOS-2 | L | 6 | HH | Single |
Table 2.
Index evaluation for the simulated data.
Table 2.
Index evaluation for the simulated data.
Filters | ENL + Increased 1 | SSI | ESI | SSIM | M-Index | KLD |
---|
None | 3.70 + 0.00 | - | - | - | - | - |
DPAD | 74.39 + 19.11 | 0.59 | 0.14 | 0.74 | 6.26 | 2.62 |
EnLee | 273.46 + 72.91 | 0.53 | 0.12 | 0.51 | 10.84 | 2.37 |
SAR-BM3-D | 1054.02 + 283.87 | 0.55 | 0.10 | 0.55 | 20.86 | 2.76 |
FANS | 1051.14 + 283.09 | 0.55 | 0.06 | 0.51 | 19.06 | 2.66 |
PPB | 539.38 + 144.78 | 0.53 | 0.27 | 0.56 | 24.41 | 2.15 |
DnCNN | 544.53 + 146.17 | 0.51 | 0.08 | 0.37 | 97.17 | 2.76 |
NL-means | 417.20 + 111.76 | 0.52 | 0.20 | 0.50 | 7.46 | 2.17 |
MDLPIA-NLM | 621.20 + 166.89 | 0.51 | 0.28 | 0.56 | 6.10 | 2.13 |
Table 3.
Index evaluation on the GF-3 SAR image.
Table 3.
Index evaluation on the GF-3 SAR image.
Filters | ENL + Increased 1 | SSI | ESI | SSIM | M-Index |
---|
None | 2.78 + 0.00 | - | - | - | - |
DPAD | 14.00 + 4.04 | 0.72 | 0.32 | 0.81 | 13.51 |
EnLee | 24.70 + 7.88 | 0.71 | 0.16 | 0.78 | 10.95 |
SAR-BM3-D | 10.18 + 2.66 | 0.75 | 0.35 | 0.84 | 32.05 |
FANS | 16.30 + 4.86 | 0.72 | 0.32 | 0.81 | 12.42 |
PPB | 50.54 + 17.18 | 0.59 | 0.23 | 0.79 | 13.76 |
DnCNN | 186.56 + 66.11 | 0.51 | 0.20 | 0.78 | 15.92 |
NL-means | 63.83 + 21.96 | 0.54 | 0.09 | 0.71 | 9.95 |
MDLPIA-NLM | 64.29 + 22.13 | 0.51 | 0.35 | 0.80 | 8.57 |
Table 4.
Index evaluation for the TerraSAR-X SAR image.
Table 4.
Index evaluation for the TerraSAR-X SAR image.
Filters | ENL + Increased 1 | SSI | ESI | SSIM | M-Index |
---|
None | 3.34 + 0.00 | - | - | - | - |
DPAD | 19.87 + 4.95 | 0.84 | 0.34 | 0.82 | 10.43 |
EnLee | 70.2520.03 | 0.89 | 0.23 | 0.62 | 13.96 |
SAR-BM3-D | 12.96 + 2.88 | 0.83 | 0.50 | 0.84 | 28.60 |
FANS | 54.78 + 15.40 | 0.85 | 0.28 | 0.77 | 10.61 |
PPB | 114.53 + 33.29 | 0.72 | 0.27 | 0.67 | 17.78 |
DnCNN | 228.75 + 67.49 | 0.63 | 0.68 | 0.38 | 21.66 |
NL-means | 105.11 + 30.47 | 0.77 | 0.19 | 0.60 | 10.43 |
MDLPIA-NLM | 116.17 + 33.78 | 0.50 | 0.55 | 0.82 | 9.75 |
Table 5.
Index evaluation for the RadarSAT-2 SAR image.
Table 5.
Index evaluation for the RadarSAT-2 SAR image.
Filters | ENL + Increased 1 | SSI | ESI | SSIM | M-Index |
---|
None | 3.35 + 0.00 | - | - | - | - |
DPAD | 46.22 + 12.80 | 0.74 | 0.26 | 0.77 | 16.60 |
EnLee | 155.60 + 45.45 | 0.70 | 0.13 | 0.57 | 32.53 |
SAR-BM3-D | 63.37 + 17.92 | 0.73 | 0.31 | 0.85 | 13.06 |
FANS | 102.95 + 29.73 | 0.71 | 0.20 | 0.71 | 13.57 |
PPB | 335.17 + 99.05 | 0.59 | 0.27 | 0.61 | 30.99 |
DnCNN | 561.05 + 166.48 | 0.59 | 0.25 | 0.33 | 12.54 |
NL-means | 50.40 + 14.04 | 0.88 | 0.60 | 0.89 | 37.68 |
MDLPIA-NLM | 239.16 + 70.39 | 0.52 | 0.50 | 0.88 | 9.18 |
Table 6.
Index evaluation for the ALOS-2 SAR image.
Table 6.
Index evaluation for the ALOS-2 SAR image.
Filters | ENL + Increased 1 | SSI | ESI | SSIM | M-Index |
---|
None | 3.60 + 0.00 | - | - | - | - |
DPAD | 130.71 + 35.31 | 0.81 | 0.20 | 0.78 | 79.85 |
EnLee | 142.55 + 38.60 | 0.78 | 0.12 | 0.60 | 37.22 |
SAR-BM3-D | 374.77 + 103.10 | 0.79 | 0.20 | 0.69 | 28.41 |
FANS | 183.02 + 49.83 | 0.76 | 0.16 | 0.66 | 29.65 |
PPB | 319.83 + 87.84 | 0.70 | 0.16 | 0.55 | 33.65 |
DnCNN | 172.93 + 47.04 | 0.70 | 0.13 | 0.34 | 26.22 |
NL-means | 171.28 + 46.58 | 0.79 | 0.23 | 0.74 | 58.46 |
MDLPIA-NLM | 184.68 + 50.30 | 0.69 | 0.25 | 0.76 | 27.41 |