{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:40:24Z","timestamp":1760164824374,"version":"build-2065373602"},"reference-count":23,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2021,5,11]],"date-time":"2021-05-11T00:00:00Z","timestamp":1620691200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Program of China","award":["2016YBF0501202"],"award-info":[{"award-number":["2016YBF0501202"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The improper setting of exposure time for the space camera will cause serious image quality degradation (overexposure or underexposure) in the imaging process. In order to solve the problem of insufficient utilization of the camera\u2019s dynamic range to obtain high-quality original images, an automatic exposure method for plane array remote sensing images based on two-dimensional entropy is proposed. First, a two-dimensional entropy-based image exposure quality evaluation model is proposed. The two-dimensional entropy matrix of the image is partitioned to distinguish the saturated areas (region of overexposure and underexposure) and the unsaturated areas (region of propitious exposure) from the original image. The ratio of the saturated area is used as an evaluating indicator of image exposure quality, which is more sensitive to the brightness, edges, information volume, and signal-to-noise ratio of the image. Then, the cubic spline interpolation method is applied to fit the exposure quality curve to efficiently improve the camera\u2019s exposure accuracy. A series of experiments have been carried out for different targets in different environments using the existing imaging system to verify the superiority and robustness of the proposed method. Compared with the conventional automatic exposure method, the signal-to-noise ratio of the image obtained by the proposed algorithm is increased by at least 1.6730 dB, and the number of saturated pixels is reduced to at least 2.568%. The method is significant to improve the on-orbit autonomous operating capability and on-orbit application efficiency of space camera.<\/jats:p>","DOI":"10.3390\/s21103306","type":"journal-article","created":{"date-parts":[[2021,5,11]],"date-time":"2021-05-11T02:14:05Z","timestamp":1620699245000},"page":"3306","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["An Automatic Exposure Method of Plane Array Remote Sensing Image Based on Two-Dimensional Entropy"],"prefix":"10.3390","volume":"21","author":[{"given":"Tan","family":"Gao","sequence":"first","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100039, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liangliang","family":"Zheng","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Xu","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yongjie","family":"Piao","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rupeng","family":"Feng","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaolong","family":"Chen","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100039, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tichao","family":"Zhou","sequence":"additional","affiliation":[{"name":"Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China"},{"name":"Key Laboratory of Space-Based Dynamic &amp; Rapid Optical Imaging Technology, Chinese Academy of Sciences, Changchun 130033, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Xia, Y., and Chen, Z. (2015, January 9\u201312). Quality Assessment for Remote Sensing Images: Approaches and Applications. Proceedings of the 2015 IEEE International Conference on Systems, Man, and Cybernetics (SMC 2015): Big Data Analytics for Human-Centric Systems, Hong Kong, China.","DOI":"10.1109\/SMC.2015.186"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Chen, G., and Zhai, M. (2019). Quality assessment on remote sensing image based on neural networks. J. Vis. Commun. Image Represent., 63.","DOI":"10.1016\/j.jvcir.2019.102580"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Chen, G., Pei, Q., and Kamruzzaman, M.M. (2020). Remote sensing image quality evaluation based on deep support value learning networks. Signal Process. Image Commun., 83.","DOI":"10.1016\/j.image.2020.115783"},{"key":"ref_4","first-page":"126","article-title":"Prediction and Validation of GF-7 Satellite Camera\u2019s Imaging Parameters Combination","volume":"41","author":"Wang","year":"2020","journal-title":"Spacecr. Recovery Remote Sens."},{"key":"ref_5","first-page":"73","article-title":"Autonomous Imaging Parameters\u2019 Adjustment Research for Space TDICCD Camera","volume":"51","author":"Cao","year":"2019","journal-title":"J. Nanjing Univ. Aeronaut. Astronaut."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Huang, S.Y., Liu, Q., Wang, H., and Ikenaga, T. (2014, January 9\u201312). Motion Area based Exposure Fusion Algorithm for Ghost Removal in High Dynamic Range Video Generation. Proceedings of the 2014 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA), Chiang Mai, Thailand.","DOI":"10.1109\/APSIPA.2014.7041597"},{"key":"ref_7","unstructured":"Ying, Z., Li, G., Ren, Y., Wang, R., and Wang, W. (2017, January 22\u201324). A New Image Contrast Enhancement Algorithm Using Exposure Fusion Framework. Proceedings of the Computer Analysis of Images in Addition, Patterns: 17th International Conference, CAIP 2017, PT II, Ystad, Sweden."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1111\/j.1467-8659.2008.01171.x","article-title":"Exposure Fusion: A Simple and Practical Alternative to High Dynamic Range Photography","volume":"28","author":"Mertens","year":"2009","journal-title":"Comput. Graph. Forum"},{"key":"ref_9","first-page":"96","article-title":"High Dynamic Range Image Synthesis for Space Target Observation","volume":"56","author":"Zeng","year":"2019","journal-title":"Laser Optoelectron. Prog."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Neves, A., Cunha, B., Pinho, A.J., and Pinheiro, I. (2009). Autonomous Configuration of Parameters in Robotic Digital Cameras, Springer.","DOI":"10.1007\/978-3-642-02172-5_12"},{"key":"ref_11","first-page":"100","article-title":"System implications of implementing auto-exposure on consumer digital cameras","volume":"3650","author":"Yeh","year":"1999","journal-title":"Proc. SPIE Int. Soc. Opt. Eng."},{"key":"ref_12","first-page":"192","article-title":"A new automatic exposure system for digital still cameras","volume":"44","author":"Kuno","year":"1998","journal-title":"IEEE (Trans.-CE)"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Montalvo, M., Guerrero, J.M., Romeo, J., Guijarro, M., and Pajares, G. (2013, January 28\u201331). Acquisition of Agronomic Images with Sufficient Quality by Automatic Exposure Time Control and Histogram Matching. Proceedings of the International Conference on Advanced Concepts for Intelligent Vision Systems, Poznan, Poland.","DOI":"10.1007\/978-3-319-02895-8_4"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Torres, J., and Menendez, J. (2015). Optimal camera exposure for video surveillance systems by predictive control of shutter speed, aperture, and gain. Real-Time Image Video Process., 9400.","DOI":"10.1117\/12.2083182"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1917","DOI":"10.1117\/1.3534855","article-title":"Using image entropy maximum for auto exposure","volume":"20","author":"Rahman","year":"2011","journal-title":"J. Electron. Imaging"},{"key":"ref_16","unstructured":"Lu, H., Hui, Z., Yang, S., and Zheng, Z. (2010, January 3\u20137). Camera parameters auto-adjusting technique for robust robot vision. Proceedings of the IEEE International Conference on Robotics and Automation, ICRA 2010, Anchorage, AK, USA."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhang, Z., Forster, C., and Scaramuzza, D. (June, January 29). Active Exposure Control for Robust Visual Odometry in HDR Environments. Proceedings of the 2017 IEEE International Conference on Robotics and Automation (ICRA), Singapore.","DOI":"10.1109\/ICRA.2017.7989449"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Shim, I., Lee, J.Y., and Kweon, I.S. (2014, January 14\u201318). Auto-adjusting camera exposure for outdoor robotics using gradient information. Proceedings of the 2014 IEEE\/RSJ International Conference on Intelligent Robots and Systems, Chicago, IL, USA.","DOI":"10.1109\/IROS.2014.6942682"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1569","DOI":"10.1109\/TCSVT.2018.2846292","article-title":"Gradient-Based Camera Exposure Control for Outdoor Mobile Platforms","volume":"29","author":"Shim","year":"2019","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Kim, J., Cho, Y., and Kim, A. (2018, January 21\u201325). Exposure Control using Bayesian Optimization based on Entropy Weighted Image Gradient. Proceedings of the 2018 IEEE International Conference on Robotics and Automation (ICRA), Brisbane, Australia.","DOI":"10.1109\/ICRA.2018.8462881"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1256","DOI":"10.1109\/TRO.2020.2985597","article-title":"Proactive Camera Attribute Control Using Bayesian Optimization for Illumination-Resilient Visual Navigation","volume":"36","author":"Kim","year":"2020","journal-title":"IEEE Trans. Robot."},{"key":"ref_22","first-page":"306","article-title":"The mathematical theory of communication (Reprinted)","volume":"14","author":"Shannon","year":"1997","journal-title":"MD Comput."},{"key":"ref_23","first-page":"29","article-title":"The Not-A-Knot Piecewise Interpolatory Cubic Polynomial","volume":"52","author":"Behforooz","year":"1992","journal-title":"Appl. Math. Comput."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/10\/3306\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:58:57Z","timestamp":1760162337000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/10\/3306"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,11]]},"references-count":23,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["s21103306"],"URL":"https:\/\/doi.org\/10.3390\/s21103306","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2021,5,11]]}}}