In this paper, we propose a new method for Synthetic Aperture Radar (SAR) image despeckling via L0-minimization strategy, which aims to smooth homogeneous areas while preserving significant structures in SAR images. We argue that the gradients of the despeckled images are sparse and can be pursued by L0-norm minimization. We then formularize the despeckling of SAR images as a global L0 optimization problem with ratio-of-average operations. Namely, the number of pixels with ratio-of-average that are unequal to one is controlled to approximate prominent structures in a sparsity-control manner. Finally, a numerical algorithm is also employed to solve the L0 optimization problem. In contrast with existing SAR image despeckling approaches, this strategy is applied without necessity to consider the local features or structures. The performance of our method is tested on high resolution X-band SAR images. The experimental results show the effectiveness of the proposed method in SAR image filtering. It outperforms many typical despeckling techniques in terms of the equivalent-number-of-looks and the edge- preserve-index. It also has some advantages compared with the existing state-of-the-art despeckling filters.
"Structure Preserving SAR Image Despeckling via L0-Minimization," Progress In Electromagnetics Research,
Vol. 141, 347-367, 2013. doi:10.2528/PIER13041503
1. Koo, V. C., Y. K. Chan, G. Vetharatnam, M. Y. Chua, C. H. Lim, C.-S. Lim, C. C. Thum, T. S. Lim, Z. Bin Ahmad, K. A. Mahmood, M. H. Bin Shahid, C. Y. Ang, W. Q. Tan, P. N. Tan, K. S. Yee, W. G. Cheaw, H. S. Boey, A. L. Choo, and B. C. Sew, "A new unmanned aerial vehicle synthetic aperture radar for environmental monitoring," Progress n Electromagnetics Research, Vol. 122, 245-268, 2012. doi:10.2528/PIER11092604
2. Fan, C., X.-T. Huang, T. Jin, J.-G. Yang, and D. X. An, "Novel pre-processing techniques for coherence improving in along-track dual-channel low frequency SAR," Progress In Electromagnetics Research, Vol. 128, 171-193, 2012.
3. Ren, S., W. Chang, T. Jin, and Z. Wang, "Automated SAR reference image preparation for navigation," Progress In Electromagnetics Research, Vol. 121, 535-555, 2011. doi:10.2528/PIER11091405
4. Li, J., S. Zhang, and J. Chang, "Applications of compressed sensing for multiple transmitters multiple azimuth beams SAR imaging," Progress In Electromagnetics Research, Vol. 127, 259-275, 2012. doi:10.2528/PIER12021307
5. Chen, J., J. Gao, Y. Zhu, W. Yang, and P. Wang, "A novel image formation algorithm for high-resolution wide-swath spaceborne SAR using compressed sensing on azimuth displacement phase center antenna," Progress In Electromagnetics Research, Vol. 125, 527-543, 2012. doi:10.2528/PIER11121101
6. Lee, J. S., "Refined filtering of image noise using local statistics," Computer Graphics and Image Processing, Vol. 15, No. 4, 380-389, 1981. doi:10.1016/S0146-664X(81)80018-4
7. Deledalle, C., L. Denis, and F. Tupin, "Iterative weighted maximum likelihood denoising with probabilistic patch-based weights," IEEE Trans. on Image Processing, Vol. 18, No. 12, 2661-2672, 2009. doi:10.1109/TIP.2009.2029593
8. Parrilli, S., M. Poderico, C. Angelino, and L. Verdoliva, "A nonlocal SAR image denoising algorithm based on LLMMSE wavelet shrinkage," IEEE Trans. on Geoscience and Remote Sensing, Vol. 50, No. 2, 606-616, 2012. doi:10.1109/TGRS.2011.2161586
9. Cheng, J., G. Gao, W. Ding, X. Ku, and J. Sun, "An improved scheme for parameter estimation of G° distribution model in high-resolution SAR images," Progress In Electromagnetics Research, Vol. 134, 23-46, 2013.
10. Wang, Y., J. Yang, W. Yin, and Y. Zhang, "A new alternating minimization algorithm for total variation image reconstruction," SIAM Journal on Imaging Sciences, Vol. 1, No. 3, 248-272, 2008. doi:10.1137/080724265
11. Xu, L., C. Lu, Y. Xu, and J. Jia, "Image smoothing via l0 gradient minimization," ACM Trans. on Graphics, Vol. 30, No. 6, 174, 2011.
12. Touzi, R., A. Lopes, and P. Bousquet, "A statistical and geometrical edge detector for SAR images," IEEE Trans. on Geoscience and Remote Sensing, Vol. 26, No. 6, 764-773, 1988. doi:10.1109/36.7708
13. Lee, J. S., J.-H. Wen, T. L. Ainsworth, K.-S. Chen, and A. J. Chen, "Improved sigma filter for speckle filtering of SAR imagery," IEEE Trans. on Geoscience and Remote Sensing, Vol. 47, No. 1, 202-213, 2009. doi:10.1109/TGRS.2008.2001637
14. Gagnon, L. and A. Jouan, "Speckle filtering of sar images: A comparative study between complex-wavelet-based and standard filters," SPIE Proceedings, Wavelet Applications in Signal and Image Processing V, Vol. 3169, 80-87, 1997. doi:10.1117/12.279681
15. Espinoza-Molina, D., D. Gleich, and M. Datcu, "Evaluation of bayesian despeckling and texture extraction methods based on Gauss-Markov and auto-binomial gibbs random fields: Application to TerraSAR-X data," IEEE Trans. on Geoscience and Remote Sensing, Vol. 50, No. 5, 2001-2025, 2012. doi:10.1109/TGRS.2011.2169679
16. Iqbal, M., J. Chen, W. Yang, P. Wang, and B. Sun, "SAR image despeckling by selective 3D filtering of multiple compressive reconstructed images," Progress In Electromagnetics Research, Vol. 134, No. 12, 209-226, 2013.
17. Lee, J. S., L. urkevich, P. Dewaele, P. Wambacq, and A. Oosterlinck, "Speckle filtering of synthetic aperture radar images: A review," Remote Sensing Reviews, Vol. 8, No. 4, 313-340, 1994. doi:10.1080/02757259409532206
18. Foucher, S., G. B. Benie, and J.-M. Boucher, "Multiscale MAP filtering of SAR images," IEEE Transactions on Image Processing, Vol. 10, No. 1, 49-60, Jan. 2001. doi:10.1109/83.892442
19. Achim, A., P. Tsakalides, and A. Bezerianos, "SAR image denoising via bayesian wavelet shrinkage based on heavy-tailed modeling," IEEE Trans. on Geoscience and Remote Sensing, Vol. 41, No. 8, 1773-1784, 2003. doi:10.1109/TGRS.2003.813488
20. Gleich, D. and M. Datcu, "Wavelet-based despeckling of SAR images using Gauss-Markov random fields," IEEE Trans. on Geoscience and Remote Sensing, Vol. 45, No. 12, 4127-4143, 2007. doi:10.1109/TGRS.2007.906093
21. Shensa, M., "The discrete wavelet transform: Wedding the a trous and mallat algorithms," IEEE Trans. on Signal Processing, Vol. 40, No. 10, 2464-2482, 1992. doi:10.1109/78.157290
22. Argenti, F. and L. Alparone, "Speckle removal from SAR images in the undecimated wavelet domain," IEEE Trans. on Geoscience and Remote Sensing, Vol. 40, No. 11, 2363-2374, 2002. doi:10.1109/TGRS.2002.805083
23. Sveinsson, J. R. and J. A. Benediktsson, "Almost translation invariant wavelet transformations for speckle reduction of SAR images," IEEE Trans. on Geoscience and Remote Sensing, Vol. 41, No. 10, 2404-2408, 2003. doi:10.1109/TGRS.2003.817844
24. Ranjani, J. J. and S. J. Thiruvengadam, "Dual-tree complex wavelet transform based SAR despeckling using interscale dependence," IEEE Trans. on Geoscience and Remote Sensing, Vol. 48, No. 6, 2723-2731, 2010. doi:10.1109/TGRS.2010.2041241
26. Frost, V., J. Stiles, K. Shanmugan, and J. Holtzman, "A model for radar images and its application to adaptive digital filtering of multiplicative noise," IEEE Trans. on Pattern Analysis and, Vol. 4, No. 2, 157-166, 1982. doi:10.1109/TPAMI.1982.4767223
27. Kuan, D., D., A. Sawchuk, T. Strand, and P. Chavel, "Adaptive noise smoothing filter for images with signal-dependent noise," IEEE Trans. on Pattern Analysis and Machine Intelligence, Vol. 7, No. 2, 165-177, 1985. doi:10.1109/TPAMI.1985.4767641
28. Lopes, A., R. Touzi, and E. Nezry, "Adaptive speckle filters and scene heterogeneity," IEEE Trans. on Geoscience and Remote Sensing, Vol. 28, No. 6, 992-1000, 1990. doi:10.1109/36.62623
29. Baraldi, A. and F. Parmiggiani, "A refined gamma map SAR speckle filter with improved geometrical adaptivity," IEEE Trans. on Geoscience and Remote Sensing, Vol. 33, No. 5, 1245-1257, 1995. doi:10.1109/36.469489
30. Xie, H., L. Pierce, and F. Ulaby, "SAR speckle reduction using wavelet denoising and Markov random field modeling," IEEE Trans. on Geoscience and Remote Sensing, Vol. 40, No. 10, 2196-2212, 2002. doi:10.1109/TGRS.2002.802473
31. Buades, A., B. Coll, and J. Morel, "A non-local algorithm for image denoising," Proc. Computer Vision and Pattern Recognition, Vol. 2, 60-65, 2005.
32. Tian, B., D.-Y. Zhu, and Z.-D. Zhu, "A novel moving target detection approach for dual-channel SAR system," Progress In Electromagnetics Research, Vol. 115, 191-206, 2011.
33. Chang, Y.-L., C.-Y. Chiang, and K.-S. Chen, "SAR image simulation with application to target recognition," Progress In Electromagnetics Research, Vol. 119, 35-57, 2011. doi:10.2528/PIER11061507
34. Mohammadpoor, M., R. S. A. Raja Abdullah, A. Ismail, and A. F. Abas, "A circular synthetic aperture radar for on-the-ground object detection," Progress In Electromagnetics Research, Vol. 122, 269-292, 2012. doi:10.2528/PIER11082201
35. Yang, W., Y. Liu, G.-S. Xia, and X. Xu, "Statistical mid-level features for building-up area extraction from full polarimetric SAR imagery," Progress In Electromagnetics Research, Vol. 132, 233-254, 2012.
36. Teng, H. T., H.-T. Ewe, and S. L. Tan, "Multifractal dimension and its geometrical terrain properties for classification of multi-band multi-polarized SAR image," Progress In Electromagnetics Research, Vol. 104, 221-237, 2010. doi:10.2528/PIER10022001
37. Park, J.-I. and K.-T. Kim, "A comparative study on ISAR imaging algorithms for radar target identification," Progress In Electromagnetics Research, Vol. 108, 155-175, 2010. doi:10.2528/PIER10071901
38. Jin, Y.-Q., "Polarimetric scattering modeling and information retrieval of SAR remote sensing - A review of FDU work," Progress In Electromagnetics Research, Vol. 104, 333-384, 2010. doi:10.2528/PIER10020101