Table 1.
Average and standard deviation value of contrast-to-noise ratios (CNRs) in the texture-free area, CNRs in the edge area, EPI, blurring index, the performance time and the visual analysis score for the different denoising methods
| Performance metric | BM3D | Gaussian | Median | TV | Original |
|---|---|---|---|---|---|
| CNRTex-free | 35.40 ± 2.02 | 36.63 ± 1.93 | 37.85 ± 2.16 | 43.7 ± 4.06 | 13.35 ± 2.35 |
| CNREdge | 6.48 ± 0.75 | 7.73 ± 0.87 | 7.87 ± 0.79 | 7.37 ± 0.74 | 4.19 ± 0.88 |
| EPI | 0.51 ± 0.10 | 0.48 ± 0.09 | 0.50 ± 0.10 | 0.52 ± 0.10 | 1 |
| Blurring index | 0.0104 ± 0.0039 | 0.0026 ± 4.04 | 0.0055 ± 0.0029 | 0.0088 ± 0.0037 | NA |
| Performance time | 301.57 ± 12.88 | 0.0997 ± 0.075 | 49.72 ± 0.71 | 17.76 ± 0.97 | NA |
| Visual analysis score (%) | |||||
| Lesion-containing teeth | 94.82 | 35.95 | 25.31 | 69.21 | 81.05 |
| Sound teeth images | 89.54 | 35 | 34.80 | 100 | 75.60 |
| Overall average | 92.18 | 35.47 | 30.05 | 84.60 | 78.32 |
BM3D, block-matching and three-dimensional; CNREdge, CNR value in the edge area; CNRTex-free, CNR value in the texture-free area; EPI, edge preserving index; NA, not available; TV, total variation.