Research Article

External Fractional-Order Gradient Vector Perona-Malik Diffusion for Sinogram Restoration of Low-Dosed X-Ray Computed Tomography

Figure 3

LDCT images in Figures 1(b) and 1(d) processed by FOPMD and EFOGV-PMD with different iteration numbers and the fractional-order . The first column: iteration number is 3; the second column: iteration number is 8 and the third column: iteration number is 15. The first row: Figure 1(b) processed by FOPMD; the second row: Figure 1(b) processed by EFOGV-PMD; the third row: Figure 1(d) processed by FOPMD and the fourth row: Figure 1(d) processed by EFOGV-PMD.
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(a) LDCT image in Figure 1(b) processed by FOPMD in [9] with , , and and iteration number is 3 
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(b) LDCT image in Figure 1(b) processed by FOPMD in [9] with , , and and iteration number is 8
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(c) LDCT image in Figure 1(b) processed by FOPMD in [9] with , , and and iteration number is 15
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(d) LDCT image in Figure 1(b) processed by EFOGV-PMD with , , and and iteration number is 3
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(e) LDCT image in Figure 1(b) processed by EFOGV-PMD with , , and and iteration number is 8
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(f) LDCT image in Figure 1(b) processed by EFOGV-PMD with , , and and iteration number is 15
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(g) LDCT image in Figure 1(d) processed by FOPMD in [9] with , , and and iteration number is 3
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(h) LDCT image in Figure 1(d) processed by FOPMD in [9] with , , and and iteration number is 8
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(i) LDCT image in Figure 1(d) processed by FOPMD in [9] with , , and and iteration number is 15
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(j) LDCT image in Figure 1(d) processed by EFOGV-PMD with , , and and iteration number is 3
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(k) LDCT image in Figure 1(d) processed by EFOGV-PMD with , , and and iteration number is 8
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(l) LDCT image in Figure 1(d) processed by EFOGV-PMD with , , and and iteration number is 15