Skip to main content
SpringerLink
Log in

Automated Detection of Low-Contrast Solar Features Using the Phase-Congruency Algorithm

  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

We propose a new feature-detection technique based on phase-congruency (PC) measurements to automatically recognize or enhance faint features in solar observations, such as off-limb coronal loops and umbral dots. Compared with other feature-detection methods that are based on gradient illuminance and imaging filtering, PC-based measurements are particular efficient for recognizing faint features, which generally have a low-intensity contrast to their surroundings. In the present article, we carry out a PC-based measurement of the local weighted mean phase angle (LWMPA) at each point in an image to indicate or highlight low-contrast features. We first used artificial images to check the detection accuracy and sensitivity to the noise of this approach. Subsequently, we applied this approach to an EUV observation obtained by the Solar Dynamics Observatory/Atmospheric Imaging Assembly to highlight off-limb coronal loops, and a photospheric observation obtained by the Hinode/Solar Optical Telescope to recognize faint dots within the cores of sunspots and pores. The results illustrate that this PC-based measurement of the LWMPA is a robust detection method for faint structures in solar observations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2
Figure 3
Figure 4

Similar content being viewed by others

References

  • Aschwanden, M.J.: 2010a, A code for automated tracing of coronal loops approaching visual perception. Solar Phys. 262, 399 – 423. 10.1007/s11207-010-9531-6 .

    Article  ADS  Google Scholar 

  • Aschwanden, M.J.: 2010b, Image processing techniques and feature recognition in solar physics. Solar Phys. 262, 235 – 275. 10.1007/s11207-009-9474-y .

    Article  ADS  Google Scholar 

  • Aschwanden, M.J., Boerner, P., Schrijver, C.J., Malanushenko, A.: 2013, Automated temperature and emission measure analysis of coronal loops and active regions observed with the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (SDO/AIA). Solar Phys. 283, 5 – 30. 10.1007/s11207-011-9876-5 .

    Article  ADS  Google Scholar 

  • Bharti, L., Hirzberger, J., Solanki, S.K.: 2013, Fine structures in the atmosphere above a sunspot umbra. Astron. Astrophys. 552, L1. 10.1051/0004-6361/201220777 .

    Article  ADS  Google Scholar 

  • Boerner, P., Edwards, C., Lemen, J., Rausch, A., Schrijver, C., Shine, R., Shing, L., Stern, R., Tarbell, T., Title, A., Wolfson, C.J., Soufli, R., Spiller, E., Gullikson, E., McKenzie, D., Windt, D., Golub, L., Podgorski, W., Testa, P., Weber, M.: 2012, Initial calibration of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Solar Phys. 275, 41 – 66. 10.1007/s11207-011-9804-8 .

    Article  ADS  Google Scholar 

  • Bovelet, B., Wiehr, E.: 2007, Multiple-scale pattern recognition applied to faint intergranular G-band structures. Solar Phys. 243, 121 – 129. 10.1007/s11207-007-9010-x .

    Article  ADS  Google Scholar 

  • Danilovic, S., Gandorfer, A., Lagg, A., Schüssler, M., Solanki, S.K., Vögler, A., Katsukawa, Y., Tsuneta, S.: 2008, The intensity contrast of solar granulation: comparing Hinode SP results with MHD simulations. Astron. Astrophys. 484, L17 – L20. 10.1051/0004-6361:200809857 .

    Article  ADS  Google Scholar 

  • de Patoul, J., Inhester, B., Feng, L., Wiegelmann, T.: 2013, 2D and 3D polar plume analysis from the three vantage positions of STEREO/EUVI A, B, and SOHO/EIT. Solar Phys. 283, 207 – 225. 10.1007/s11207-011-9902-7 .

    Article  ADS  Google Scholar 

  • Feng, S., Ji, K.-f., Deng, H., Wang, F., Fu, X.-d.: 2012, Automatic detection and extraction algorithm of inter-granular bright points. J. Korean Astron. Soc. 45, 167 – 173.

    Article  ADS  Google Scholar 

  • Feng, S., Deng, L., Yang, Y., Ji, K.: 2013, Statistical study of photospheric bright points in an active region and quiet Sun. Astrophys. Space Sci. 348, 17 – 24. 10.1007/s10509-013-1555-6 .

    Article  ADS  Google Scholar 

  • Gallagher, P.T., Young, C.A., Byrne, J.P., McAteer, R.T.J.: 2011, Coronal mass ejection detection using wavelets, curvelets and ridgelets: applications for space weather monitoring. Adv. Space Res. 47, 2118 – 2126. 10.1016/j.asr.2010.03.028 .

    Article  ADS  Google Scholar 

  • Gao, J., Wang, H., Zhou, M.: 2002, Development of an automatic filament disappearance detection system. Solar Phys. 205, 93 – 103.

    Article  ADS  Google Scholar 

  • Hamedivafa, H.: 2008, Application of an improved method of image segmentation and some considerations on identification and tracking of umbral dots. Solar Phys. 250, 17 – 29. 10.1007/s11207-008-9201-0 .

    Article  ADS  Google Scholar 

  • Hao, Q., Fang, C., Chen, P.F.: 2013, Developing an advanced automated method for solar filament recognition and its scientific application to a solar cycle of MLSO Hα data. Solar Phys. 286, 385 – 404.

    Article  ADS  Google Scholar 

  • Kovesi, P.: 1999, Image features from phase congruency. Videre: J. Comp. Vision Res. 1(3), 1 – 26.

    Google Scholar 

  • Kovesi, P.: 2000, Phase congruency: a low-level image invariant. Psychol. Res. 64(2), 136 – 148.

    Article  Google Scholar 

  • Lemen, J.R., Title, A.M., Akin, D.J., Boerner, P.F., Chou, C., Drake, J.F., Duncan, D.W., Edwards, C.G., Friedlaender, F.M., Heyman, G.F., Hurlburt, N.E., Katz, N.L., Kushner, G.D., Levay, M., Lindgren, R.W., Mathur, D.P., McFeaters, E.L., Mitchell, S., Rehse, R.A., Schrijver, C.J., Springer, L.A., Stern, R.A., Tarbell, T.D., Wuelser, J.-P., Wolfson, C.J., Yanari, C., Bookbinder, J.A., Cheimets, P.N., Caldwell, D., Deluca, E.E., Gates, R., Golub, L., Park, S., Podgorski, W.A., Bush, R.I., Scherrer, P.H., Gummin, M.A., Smith, P., Auker, G., Jerram, P., Pool, P., Soufli, R., Windt, D.L., Beardsley, S., Clapp, M., Lang, J., Waltham, N.: 2012, The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Solar Phys. 275, 17 – 40. 10.1007/s11207-011-9776-8 .

    Article  ADS  Google Scholar 

  • Maurya, R.A., Ambastha, A.: 2010, A technique for automated determination of flare ribbon separation and energy release. Solar Phys. 262, 337 – 353. 10.1007/s11207-009-9488-5 .

    Article  ADS  Google Scholar 

  • Morrone, M.C., Owens, R.: 1987, Feature detection from local energy. Pattern Recognit. Lett. 6(5), 303 – 313.

    Article  Google Scholar 

  • Morrone, M.C., Ross, J., Burr, D.C., Owens, R.: 1986, Mach bands are phase dependent. Nature 324(6094), 250 – 253.

    Article  ADS  Google Scholar 

  • Oppenheim, A.V., Lim, J.S.: 1981, The importance of phase in signals. Proc. IEEE 69(5), 529 – 541.

    Article  ADS  Google Scholar 

  • Qu, M., Shih, F.Y., Jing, J., Wang, H.: 2005, Automatic solar filament detection using image processing techniques. Solar Phys. 228, 119 – 135.

    Article  ADS  Google Scholar 

  • Riethmüller, T.L., Solanki, S.K., Zakharov, V., Gandorfer, A.: 2008, Brightness, distribution, and evolution of sunspot umbral dots. Astron. Astrophys. 492, 233 – 243. 10.1051/0004-6361:200810701 .

    Article  ADS  Google Scholar 

  • Shimizu, T., Nagata, S., Tsuneta, S., Tarbell, T., Edwards, C., Shine, R., Hoffmann, C., Thomas, E., Sour, S., Rehse, R., Ito, O., Kashiwagi, Y., Tabata, M., Kodeki, K., Nagase, M., Matsuzaki, K., Kobayashi, K., Ichimoto, K., Suematsu, Y.: 2008, Image stabilization system for Hinode (Solar-B) solar optical telescope. Solar Phys. 249, 221 – 232. 10.1007/s11207-007-9053-z .

    Article  ADS  Google Scholar 

  • Sobotka, M., Bonet, J.A., Vazquez, M.: 1992, On the relation between the intensities of bright features and the local background in sunspot umbrae. Astron. Astrophys. 257, 757 – 762.

    ADS  Google Scholar 

  • Sobotka, M., Brandt, P.N., Simon, G.W.: 1997, Fine structure in sunspots. I. Sizes and lifetimes of umbral dots. Astron. Astrophys. 328, 682 – 688.

    ADS  Google Scholar 

  • Sobotka, M., Hanslmeier, A.: 2005, Photometry of umbral dots. Astron. Astrophys. 442, 323 – 329. 10.1051/0004-6361:20053299 .

    Article  ADS  Google Scholar 

  • Tavabi, E., Koutchmy, S., Ajabshirizadeh, A.: 2013, Increasing the fine structure visibility of the Hinode SOT Ca ii H filtergrams. Solar Phys. 283, 187 – 194. 10.1007/s11207-012-0011-z .

    Article  ADS  Google Scholar 

  • Tsuneta, S., Ichimoto, K., Katsukawa, Y., Nagata, S., Otsubo, M., Shimizu, T., Suematsu, Y., Nakagiri, M., Noguchi, M., Tarbell, T., Title, A., Shine, R., Rosenberg, W., Hoffmann, C., Jurcevich, B., Kushner, G., Levay, M., Lites, B., Elmore, D., Matsushita, T., Kawaguchi, N., Saito, H., Mikami, I., Hill, L.D., Owens, J.K.: 2008, The solar optical telescope for the Hinode mission: an overview. Solar Phys. 249, 167 – 196. 10.1007/s11207-008-9174-z .

    Article  ADS  Google Scholar 

  • Xie, Z.X., Yu, D.R., Zhang, J., Yang, S.H., Hu, Q.H.: 2009, Properties of magnetic elements in the quiet Sun using the marker-controlled watershed method. Astron. Astrophys. 505, 801 – 810. 10.1051/0004-6361/200810946 .

    Article  ADS  Google Scholar 

  • Yu, D., Xie, Z., Hu, Q., Yang, S., Zhang, J., Wang, J.: 2011, Physical properties of large and small granules in solar quiet regions. Astrophys. J. 743, 58. 10.1088/0004-637X/743/1/58 .

    Article  ADS  Google Scholar 

  • Zhang, Y., Ichimoto, K.: 2013, Properties of sunspot penumbral grains observed with Hinode. Astron. Astrophys. 560, A77. 10.1051/0004-6361/201118119 .

    Article  ADS  Google Scholar 

Download references

Acknowledgements

This work is supported by the National Natural Science Foundation of China (grants Nos. U1231205, 11163004, 11263004, 11103075, 11303011) and by the Open Research Program of Key Laboratory of Solar Activity of the Chinese Academy of Sciences (No. KLSA201309). This work is also supported by the Opening Project of Key Laboratory of Astronomical Optics and Technology, Nanjing Institute of Astronomical Optics and Technology, Chinese Academy of Sciences (No. CAS-KLAOT-KF201306), and the Open Fund of the Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, China. Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in cooperation with ESA and NSC (Norway). We acknowledge the use of the SDO/AIA observations for this study.

Author information

Authors and Affiliations

  1. Yunnan Key Laboratory of Computer Technology Application, Faculty of Information Engineering and Automation, Kunming University of Science and Technology, Kunming, 650500, China

    Song Feng, Feng Wang, Hui Deng, Yunfei Yang & Kaifan Ji

  2. Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, China

    Song Feng & Yunfei Yang

  3. Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, Ministry of Education, Nanjing, 210093, China

    Song Feng & Yunfei Yang

  4. Yunnan Astronomical Observatory, National Astronomical Observatories, Chinese Academy of Sciences, Kunming, 650011, China

    Zhi Xu

Authors
  1. Song Feng
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Zhi Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Feng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Hui Deng
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Yunfei Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Kaifan Ji
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kaifan Ji.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Feng, S., Xu, Z., Wang, F. et al. Automated Detection of Low-Contrast Solar Features Using the Phase-Congruency Algorithm. Sol Phys 289, 3985–3994 (2014). https://doi.org/10.1007/s11207-014-0538-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11207-014-0538-2

Keywords

Search

Navigation