\`x^2+y_1+z_12^34\`
Advanced Search
Article Contents
Article Contents

An adaptive total variational despeckling model based on gray level indicator frame

  • * Corresponding author: Zhichang Guo

    * Corresponding author: Zhichang Guo 
This work is partially supported by the National Natural Science Foundation of China (11971131, U1637208, 61873071, 51476047, 11871133, 71773024), the Natural Sciences Foundation of Heilongjiang Province of China (LC2018001, G2018006) and the Heilongjiang Postdoctoral Scientific Research Developmental Fund (LBH-Q18064)
Abstract Full Text(HTML) Figure(21) / Table(2) Related Papers Cited by
  • For the characteristics of the degraded images with multiplicative noise, the gray level indicators for constructing adaptive total variation are proposed. Based on the new regularization term, we propose the new convex adaptive variational model. Then, considering the existence, uniqueness and comparison principle of the minimizer of the functional. The finite difference method with rescaling technique and the primal-dual method with adaptive step size are used to solve the minimization problem. The paper ends with a report on numerical tests for the denoising of images subject to multiplicative noise, the comparison with other methods is provided as well.

    Mathematics Subject Classification: Primary:68U10, 68Q25;Secondary:32A70.

    Citation:

    \begin{equation} \\ \end{equation}
  • 加载中
  • Figure 1.  The relation between the influence of the noise and the gray levels. (a)1D original ladder-shaped signal; (b)1D speckle noise with mean of 1 and $ L = 4 $; (c) the comparison of original signal and speckle-corrupted signal; (d) The gray area shows values between the first and third quartiles, the dots represent the expectation and the blue line a single noisy realization. Expectation and quartiles are computed from 10000 noisy realizations

    Figure 2.  Pretreatment effect map. The black curve is the original signal, and the green curve is the observed signal which has polluted by the Gamma noise with a standard deviation of $ 1/\sqrt{6} $ ($ L $ = 6). The red curve is result of preprocessing

    Figure 3.  Adjustment for $ \alpha $. In the first row, the red curves are the observed signal which have polluted by the Gamma noise with a standard deviation of 1/2 (L = 4). In the second line, the blue and green curves represent the corresponding $ \alpha $ and $ \alpha^{'} $ respectively

    Figure 4.  Comparison of AA, DZ and our model for multiplicative noise removal. The red curve is the denoising relization of the observed signals by each model. The random Gamma noise with a standard deviation of 1/$ \sqrt{6} $ ($ L $ = 6)

    Figure 5.  Comparison of AA, DZ and our model for multiplicative noise removal. The random Gamma noise with a mean of 1 and a standard deviation of 1/2 (L = 4)

    Figure 6.  Pie image (214 $ \times $ 216, $ L $ = 1.)

    Figure 7.  Pie image (214 $ \times $ 216, $ L $=4.)

    Figure 8.  Pie image (214 $ \times $ 216, $ L $ = 10.)

    Figure 9.  Cameraman image (256 $ \times $ 256, $ L $ = 1)

    Figure 10.  Cameraman image (256 $ \times $ 256, $ L $=4)

    Figure 11.  Cameraman image (256 $ \times $ 256, $ L $ = 10)

    Figure 12.  Parrot image (512 $ \times $ 512, $ L $ = 1.)

    Figure 13.  Parrot image (512 $ \times $ 512, $ L $=4.)

    Figure 14.  Parrot image (512 $ \times $ 512, $ L $ = 10.)

    Figure 15.  Synthetic image (300 $ \times $ 300, $ L $ = 1.)

    Figure 16.  Synthetic image (300 $ \times $ 300, $ L $=4.)

    Figure 17.  Synthetic image (300 $ \times $ 300, $ L $ = 10.)

    Figure 18.  Piglet image ($ 341 \times 199 $, $ L $ = 1.)

    Figure 19.  Piglet image ($ 341 \times 199 $, $ L $=4.)

    Figure 20.  Piglet image ($ 341 \times 199 $, $ L $ = 10.)

    Figure 21.  Plots of Energy and PSNR of $ \tilde{u}^{k} $. The first column is about Pie(L=10) and the second column is about Cameraman(L=4)

    Table 1.  Parameters used in the comparison study

    Parameters
    Algorithm $ L=1 $ $ L=4 $ $ L=10 $
    The Pie image (214 $ \times $ 216)
    AA ($ \lambda $) 5e-4 0.2 22
    DZ ($ \alpha,\lambda $) 0.3, 0.2 0.5, 0.04 5, 0.03
    $ E_{1} $-FDM ($ \lambda,\beta,p $) 3e-7, 3e-8, 1.3 2e-3, 1e-3, 1.3 2e-3, 1e-3, 1.3
    $ E_{2} $-FDM ($ \lambda,\beta,p,a $) 1e-7, 1e-8, 1.39, 0.74 2e-3, 1e-3, 1.39, 0.74 2e-3, 3e-3, 1.39, 0.74
    $ E_{1} $-PDM ($ \lambda,\beta,p $) 4e-3, 6e-3, 1.3 4e-3, 5e-3, 1.3 3e-3, 6e-3, 1.3
    $ E_{2} $-PDM ($ \lambda,\beta,p,a $) 4e-2, 6e-3, 1.39, 0.74 4e-3, 5e-3, 1.38, 0.74 4e-3, 4e-3, 1.34, 0.74
    The Cameraman image($ 256\times256 $)
    AA ($ \lambda $) 0.18 40 75
    DZ ($ \alpha,\lambda $) 0.21, 0.25 1.6, 0.11 2.5, 0.03
    $ E_{1} $-FDM ($ \lambda,\beta,p $) 1e-7, 5e-7, 1.3 2e-3, 2e-3, 1.3 3e-2, 2e-2, 1.3
    $ E_{2} $-FDM ($ \lambda,\beta,p,a $) 3e-7, 2e-7, 1.3, 0.8 3e-3, 2e-3, 1.33, 0.76 3e-2, 2e-2, 1.4, 0.78
    $ E_{1} $-PDM ($ \lambda,\beta,p $) 6e-3, 8e-3, 1.3 8e-3, 6e-3, 1.3 8e-3, 3e-3, 1.3
    $ E_{2} $-PDM ($ \lambda,\beta,p,a $) 1e-2, 6e-3, 1.3, 0.79 8e-3, 4e-3, 1.3, 0.75 6e-3, 6e-3, 1.3, 0.75
    The Parrot image($ 512\times512 $)
    AA ($ \lambda $) 0.6 1.5 8
    DZ ($ \alpha,\lambda $) 0.11, 0.2 1, 0.2 15, 0.3
    $ E_{1} $-FDM ($ \lambda,\beta,p $) 2e-6, 2e-6, 1.3 1e-4, 1e-4, 1.3 3e-3, 3e-3, 1.3
    $ E_{2} $-FDM ($ \lambda,\beta,p,a $) 1e-6, 1e-6, 1.36, 0.74 1e-4, 1e-4, 1.35, 0.74 1e-3, 1e-3, 1.32, 0.74
    $ E_{1} $-PDM ($ \lambda,\beta,p $) 6e-3, 6e-3, 1.3 6e-3, 6e-3, 1.3 6e-3, 6e-3, 1.3
    $ E_{2} $-PDM ($ \lambda,\beta,p,a $) 6e-3, 6e-3, 1.36, 0.74 6e-3, 6e-3, 1.34, 0.74 6e-3, 6e-3, 1.32, 0.74
    The Synthetic image($ 300\times300 $)
    AA ($ \lambda $) 7e-4 4e-3 1e-3
    DZ ($ \alpha,\lambda $) 0.117, 0.125 0.155, 0.1 0.11, 0.2
    $ E_{1} $-FDM ($ \lambda,\beta,p $) 1e-7, 1e-7, 1.3 2e-4, 2e-4, 1.3 1e-3, 1e-3, 1.3
    $ E_{2} $-FDM ($ \lambda,\beta,p,a $) 1e-7, 1e-7, 1.35, 0.78 1e-4, 1e-4, 1.36, 0.74 1e-3, 1e-3, 1.35, 0.74
    $ E_{1} $-PDM ($ \lambda,\beta,p $) 4e-3, 5e-3, 1.3 4e-3, 4e-3, 1.3 4e-3, 4e-3, 1.3
    $ E_{2} $-PDM ($ \lambda,\beta,p,a $) 4e-3, 5e-3, 1.4, 0.75 4e-3, 5e-3, 1.4, 0.74 4e-3, 4e-3, 1.32, 0.74
    The Piglet image($ 341\times199 $)
    AA ($ \lambda $) 5e-3 80 190
    DZ ($ \alpha,\lambda $) 3e-3, 0.16 2e-3, 3e-2 0.1, 7e-3
    $ E_{1} $-FDM ($ \lambda,\beta,p $) 1e-7, 9e-8, 1.3 1e-4, 1e-4, 1.3 1e-3, 1e-3, 1.3
    $ E_{2} $-FDM ($ \lambda,\beta,p,a $) 2e-7, 9e-8, 1.38, 0.74 1e-4, 1e-4, 1.37, 0.74 1e-3, 1e-3, 1.39, 0.74
    $ E_{1} $-PDM ($ \lambda,\beta,p $) 4e-3, 4e-3, 1.3 4e-3, 7e-3, 1.3 6e-3, 8e-3, 1.3
    $ E_{2} $-PDM ($ \lambda,\beta,p,a $) 4e-3, 7e-3, 1.35, 0.74 4e-3, 7e-3, 1.35, 0.74 6e-3, 8e-3, 1.32, 0.74
     | Show Table
    DownLoad: CSV

    Table 2.  Comparison of PSNR, MAE, SSIM and iterations

    PSNR MAE SSIM #iter
    $ L $ $ 1 $ $ 4 $ $ 10 $ $ 1 $ $ 4 $ $ 10 $ $ 1 $ $ 4 $ $ 10 $ $ 1 $ $ 4 $ $ 10 $
    The Pie image($ 214\times216 $)
    AA $ 13.12 $ $ 18.43 $ $ 22.20 $ $ 42.51 $ $ 22.66 $ $ 13.40 $ 0.57 0.77 0.88 1978 743 464
    DZ $ 14.25 $ $ 19.94 $ $ 23.45 $ $ 32.77 $ $ 16.26 $ $ 10.14 $ 0.63 0.86 0.92 637 1162 1027
    $ E_{1} $-FDM $ 17.26 $ $ 21.35 $ $ 24.00 $ $ 23.71 $ $ 14.33 $ 10.15 0.67 0.84 0.90 481 275 273
    $ E_{2} $-FDM $ 17.45 $ $ 21.30 $ 24.08 $ 23.50 $ $ 14.44 $ 10.10 0.69 0.84 0.90 362 256 211
    $ E_{1} $-PDM $ 17.22 $ $ 21.30 $ $ 23.86 $ $ 24.00 $ $ 14.29 $ $ 10.15 $ 0.71 0.84 0.90 1973 609 312
    $ E_{2} $-PDM $ 17.46 $ $ 21.21 $ $ 23.87 $ $ 23.19 $ $ 14.53 $ $ 10.28 $ 0.71 0.83 0.90 1475 485 239
    The cameraman image($ 256\times256 $)
    AA 19.06 22.96 25.09 16.79 10.09 7.94 0.56 0.69 0.74 1800 672 351
    DZ 19.34 22.81 25.22 16.64 10.45 7.94 0.53 0.70 0.75 387 291 338
    $ E_{1} $-FDM 21.56 24.44 26.37 12.95 9.19 7.29 0.63 0.71 0.77 442 361 289
    $ E_{2} $-FDM 21.56 24.50 26.42 12.98 9.18 7.27 0.63 0.71 0.76 395 315 238
    $ E_{1} $-PDM 21.70 24.28 26.21 12.60 9.01 7.29 0.65 0.73 0.78 1469 455 243
    $ E_{2} $-PDM 21.76 24.30 26.23 11.96 9.00 7.35 0.66 0.73 0.77 1167 382 203
    The Parrot image($ 512\times512 $)
    AA 20.52 24.46 26.89 14.73 10.15 7.86 0.60 0.68 0.72 1833 666 359
    DZ 20.59 25.19 27.52 14.22 9.38 7.29 0.57 0.71 0.76 533 187 69
    $ E_{1} $-FDM 23.84 26.73 28.57 10.88 7.95 6.49 0.66 0.74 0.78 445 391 342
    $ E_{2} $-FDM 23.84 26.75 28.61 10.96 8.00 6.48 0.65 0.73 0.78 372 309 227
    $ E_{1} $-PDM 23.88 26.73 28.55 10.93 7.94 6.50 0.65 0.73 0.78 1907 629 323
    $ E_{2} $-PDM 23.81 26.71 28.60 11.96 9.00 6.48 0.65 0.73 0.78 1572 523 240
    The Synthetic image($ 300\times300 $)
    AA $ 22.31 $ $ 27.44 $ $ 30.43 $ $ 11.90 $ $ 6.32 $ $ 4.35 $ 0.81 0.88 0.92 2664 1010 643
    DZ $ 22.43 $ $ 27.90 $ $ 30.54 $ $ 10.30 $ $ 5.42 $ $ 4.04 $ 0.77 0.94 0.96 1195 570 291
    $ E_{1} $-FDM $ 24.71 $ $ 29.08 $ $ 31.68 $ $ 9.02 $ $ 4.88 $ 3.30 0.84 0.93 0.95 507 442 371
    $ E_{2} $-FDM $ 24.77 $ $ 29.07 $ 31.71 $ 8.61 $ $ 4.94 $ 3.41 0.83 0.92 0.95 457 337 282
    $ E_{1} $-PDM $ 25.44 $ $ 28.89 $ $ 31.46 $ $ 7.30 $ $ 4.29 $ $ 3.24 $ 0.89 0.93 0.96 2506 787 425
    $ E_{2} $-PDM $ 25.36 $ $ 28.93 $ $ 31.42 $ $ 7.43 $ $ 4.43 $ $ 3.24 $ 0.89 0.92 0.96 1759 645 338
    The Piglet image($ 341 \times 199 $)
    AA $ 21.70 $ $ 26.96 $ $ 30.08 $ $ 12.27 $ $ 6.88 $ $ 4.72 $ 0.83 0.89 0.91 2363 1068 660
    DZ $ 21.74 $ $ 27.17 $ $ 30.18 $ $ 11.94 $ $ 6.67 $ $ 4.66 $ 0.73 0.89 0.91 739 1540 4440
    $ E_{1} $-FDM $ 24.92 $ $ 28.45 $ $ 30.89 $ $ 9.65 $ $ 6.08 $ 4.53 0.82 0.89 0.92 499 390 345
    $ E_{2} $-FDM $ 24.82 $ $ 28.51 $ 30.75 $ 9.44 $ $ 5.88 $ 4.58 0.78 0.88 0.91 432 321 297
    $ E_{1} $-PDM $ 24.96 $ $ 28.33 $ $ 30.68 $ $ 8.99 $ $ 5.95 $ $ 4.58 $ 0.84 0.88 0.91 1904 666 335
    $ E_{2} $-PDM $ 24.89 $ $ 28.31 $ $ 30.68 $ $ 9.12 $ $ 5.96 $ $ 4.46 $ 0.80 0.88 0.92 1463 530 280
     | Show Table
    DownLoad: CSV
  • [1] G. Aubert and J.-F. Aujol, A variational approach to remove multiplicative noise, SIAM Journal on Applied Mathematics, 68 (2008), 925-946.  doi: 10.1137/060671814.
    [2] A. Beck and M. Teboulle, Fast gradient-based algorithms for constrained total variation image denoising and deblurring problems, IEEE Transactions on Image Processing, 18 (2009), 2419-2434.  doi: 10.1109/TIP.2009.2028250.
    [3] A. C. BovikT. S. Huang and D. C. Munson, A generalization of median filtering using linear combinations of order statistics, IEEE Trans Acoustics Speech Signal Processing, 31 (1983), 1342-1350. 
    [4] A. C. BovikT. S. Huang and D. C. Munson, The effect of median filtering on edge estimation and detection, IEEE Transactions on Pattern Analysis and Machine Intelligence, 9 (1987), 181-194.  doi: 10.1109/TPAMI.1987.4767894.
    [5] K. BrediesK. Kunisch and T. Pock, Total generalized variation, SIAM Journal on Imaging Sciences, 3 (2010), 492-526.  doi: 10.1137/090769521.
    [6] A. Chambolle, An algorithm for total variation minimization and applications, Journal of Mathematical Imaging and Vision, 20 (2004), 89-97. 
    [7] A. Chambolle, An algorithm for mean curvature motion, Interfaces and Free Boundaries, 6 (2004), 195-218.  doi: 10.4171/IFB/97.
    [8] A. Chambolle and T. Pock, A first-order primal-dual algorithm for convex problems with applications to imaging, Journal of Mathematical Imaging and Vision, 40 (2011), 120-145.  doi: 10.1007/s10851-010-0251-1.
    [9] C. ChauxJ.-C. Pesquet and N. Pustelnik, Nested iterative algorithms for convex constrained image recovery problems, SIAM Journal on Imaging Sciences, 2 (2009), 730-762.  doi: 10.1137/080727749.
    [10] Y. Chen and M. Rao, Minimization problems and associated flows related to weighted p energy and total variation, SIAM Journal on mathematical Analysis, 34 (2003), 1084-1104.  doi: 10.1137/S0036141002404577.
    [11] Y. Chen and T. Wunderli, Adaptive total variation for image restoration in BV space, Journal of Mathematical Analysis and Applications, 272 (2002), 117-137.  doi: 10.1016/S0022-247X(02)00141-5.
    [12] P. L. Combettes and J.-C. Pesquet, A douglas-rachford splitting approach to nonsmooth convex variational signal recovery, IEEE Journal of Selected Topics in Signal Processing, 1 (2007), 564-574.  doi: 10.1109/JSTSP.2007.910264.
    [13] A. Dauwe, B. Goossens, H. Luong and W. Philips, A fast non-local image denoising algorithm, Electronic Imaging, 6812 (2008), 681210. doi: 10.1117/12.765505.
    [14] C.-A. Deledalle, L. Denis, S. Tabti and F. Tupin, MuLoG, or how to apply Gaussian denoisers to multi-channel SAR speckle reduction?, IEEE Transactions on Image Processing, 26 (2017), 4389-4303. doi: 10.1109/TIP.2017.2713946.
    [15] G. DongZ. Guo and B. Wu, A convex adaptive total variation model based on the gray level indicator for multiplicative noise removal, Abstract and Applied Analysis, 2013 (2013), 1-21.  doi: 10.1155/2013/912373.
    [16] Y. Dong and T. Zeng, A convex variational model for restoring blurred images with multiplicative noise, SIAM Journal on Imaging Sciences, 6 (2013), 1598-1625.  doi: 10.1137/120870621.
    [17] S. DurandJ. Fadili and M. Nikolova, Multiplicative noise removal using L1 fidelity on frame coefficients, Journal of Mathematical Imaging and Vision, 36 (2010), 201-226.  doi: 10.1007/s10851-009-0180-z.
    [18] E. EsserX. Zhang and T. F. Chan, A general framework for a class of first order primal-dual algorithms for convex optimization in imaging science, Siam Journal on Imaging Sciences, 3 (2010), 1015-1046.  doi: 10.1137/09076934X.
    [19] K. FlorianB. KristianP. Thomas and S. Rudolf, Second order total generalized variation (TGV) for MRI, Magnetic Resonance in Medicine, 65 (2011), 480-491.  doi: 10.1002/mrm.22595.
    [20] E. Giusti, Minimal surfaces and functions of bounded variation, Monographs in Mathematics, Birkhäuser Verlag, Basel, 80 1984, 7-26. doi: 10.1007/978-1-4684-9486-0.
    [21] T. Goldstein and S. Osher, The split Bregman method for L1-regularized problems, SIAM Journal on Imaging Sciences, 2 (2009), 323-343.  doi: 10.1137/080725891.
    [22] H. NaM. KangM. Jung and M. Kang, Nonconvex TGV regularization model for multiplicative noise removal with spatially varying parameters, Inverse Problems and Imaging, 13 (2019), 117-147.  doi: 10.3934/ipi.2019007.
    [23] P. KornprobstR. Deriche and G. Aubert, Image sequence analysis via partial differential equations, Journal of Mathematical Imaging and Vision, 11 (1999), 5-26.  doi: 10.1023/A:1008318126505.
    [24] K. DabovA. FoiV. Katkovnik and K. Egiazarian, Image denoising by sparse 3-D transform-domain collaborative filtering, IEEE Transactions on Image Processing, 16 (2007), 2080-2095.  doi: 10.1109/TIP.2007.901238.
    [25] T. LeR. Chartrand and T. J. Asaki, A variational approach to reconstructing images corrupted by poisson noise, Journal of Mathematical Imaging and Vision, 27 (2007), 257-263.  doi: 10.1007/s10851-007-0652-y.
    [26] S. ParrilliM. PodericoC. V. Angelino and L. Verdoliva, A nonlocal SAR image denoising algorithm based on LLMMSE wavelet shrinkage, IEEE Transactions on Geoscience and Remote Sensing, 50 (2012), 606-616.  doi: 10.1109/TGRS.2011.2161586.
    [27] P. Perona and J. Malik, Scale-space and edge detection using anisotropic diffusion, IEEE Transactions on Pattern Analysis and Machine Intelligence, 12 (1990), 629-639.  doi: 10.1109/34.56205.
    [28] T. Pock, D. Cremers, H. Bischof and A. Chambolle, An algorithm for minimizing the mumford-Shah functional, IEEE International Conference on Computer Vision, (2009), 1133-1140. doi: 10.1109/ICCV.2009.5459348.
    [29] L. I. RudinS. Osher and E. Fatemi, Nonlinear total variation based noise removal algorithms, Physica D: Nonlinear Phenomena, 60 (1992), 259-268.  doi: 10.1016/0167-2789(92)90242-F.
    [30] C. Poynton, Digital Video and HD: Algorithms and Interfaces, 2$^nd$ edition, Elsevier, USA, 2012. doi: 10.1016/C2010-0-68987-5.
    [31] X. ShanJ. Sun and Z. Guo, Multiplicative noise removal based on the smooth diffusion equation, Journal of Mathematical Imaging and Vision, 61 (2019), 763-779.  doi: 10.1007/s10851-018-00870-z.
    [32] R. Soorajkumar, P. K. Kumar, D. Girish and J. Rajan, Fourth order PDE based ultrasound despeckling using ENI classification, IEEE International Conference on Signal Processing and Communications (SPCOM), (2016). doi: 10.1109/SPCOM.2016.7746633.
    [33] D. M. Strong and T. F. Chan, Spatially and scale adaptive total variation based regularization and anisotropic diffusion in image processing, Journal of Mathematical Imaging and Vision, (1996).
    [34] M. TurK. C. Chin and J. W. Goodman, When is speckle noise multiplicative?, Applied Optics, 21 (1982), 1157-1159.  doi: 10.1364/AO.21.001157.
    [35] L. Verdoliva, R. Gaetano, G. Ruello and G. Poggi, Optical-driven nonlocal SAR despeckling, IEEE Geoscience and Remote Sensing Letters, 12 (2015), 314-318. doi: 10.1109/LGRS.2014.2337515.
    [36] Z. WangA. C. Bovik and H. R. Sheikh, Image quality assessment: from error visibility to structural similarity, IEEE Transactions on Image Processing, 53 (2015), 2765-2774. 
    [37] J. Weickert, Anisotropic Diffusion in Image Processing, Teubner Stuttgart, ECMI Series, Teubner, Stuttgart, 1998.
    [38] C. Wu and X.-C. Tai, Augmented Lagrangian method, dual Methods, and split Bregman iteration for ROF, vectorial TV, and high order models, SIAM Journal on Imaging Sciences, 3 (2010), 300-339.  doi: 10.1137/090767558.
    [39] J.-H. YangX.-L. ZhaoT.-H. MaY. ChenT.-Z. Huang and M. Ding, Emote sensing images destriping using unidirectional hybrid total variation and nonconvex low-rank regularization, Journal of Computational and Applied Mathematics, 363 (2020), 124-144.  doi: 10.1016/j.cam.2019.06.004.
    [40] X.-L. ZhaoF. Wang and M. K. Ng, A new convex optimization model for multiplicative noise and blur removal, SIAM Journal on Imagingences, 7 (2014), 456-475.  doi: 10.1137/13092472X.
    [41] Y. ZhaoJ. G. LiuB. ZhangW. Hong and Y.-R. Wu, Adaptive total variation regularization based SAR image despeckling and despeckling evaluation index, IEEE Transactions on Geoscience and Remote Sensing, 53 (2015), 2765-2774.  doi: 10.1109/TGRS.2014.2364525.
    [42] Z. ZhouZ. GuoG. DongJ. SunD. Zhang and B. Wu, A doubly degenerate diffusion model based on the gray level indicator for multiplicative noise removal, IEEE Transactions on Image Processing, 24 (2015), 249-260.  doi: 10.1109/TIP.2014.2376185.
  • 加载中
Open Access Under a Creative Commons license

Figures(21)

Tables(2)

SHARE

Article Metrics

HTML views(1166) PDF downloads(397) Cited by(0)

Access History

Other Articles By Authors

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return