In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes consid...In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation patterns.This paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary learning.In the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time autocorrelation.Online dictionary learning is followed to separate real signals from jamming slices.Under the learned representation,time-varying MISRJs are suppressed effectively.Both simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods.展开更多
针对基于学习的人脸超分辨率算法噪点、伪影较多,且噪声鲁棒性较差的问题,提出一种基于在线字典学习的人脸超分辨率重建算法。以人脸图集作为训练图库,运用在线字典学习方法提高字典训练的精度。独立调整字典学习阶段的正则化参数λt和...针对基于学习的人脸超分辨率算法噪点、伪影较多,且噪声鲁棒性较差的问题,提出一种基于在线字典学习的人脸超分辨率重建算法。以人脸图集作为训练图库,运用在线字典学习方法提高字典训练的精度。独立调整字典学习阶段的正则化参数λt和求解重建稀疏系数阶段的λr,以获取最优的超完备字典和稀疏系数用于图像重建。实验结果表明,目标图像峰值信噪比比同一类型的稀疏编码超分法平均提高了0.85 d B,结构相似性增加了0.013 3,有效地抑制了噪点和伪影。在含噪人脸图像应用中,噪声水平提高时,峰值信噪比下降相对较平缓,提升人脸超分效果的同时改善了算法的噪声鲁棒性。展开更多
基金supported by the National Natural Science Foundation of China(61771372,61771367,62101494)the National Outstanding Youth Science Fund Project(61525105)+1 种基金Shenzhen Science and Technology Program(KQTD20190929172704911)the Aeronautic al Science Foundation of China(2019200M1001)。
文摘In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation patterns.This paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary learning.In the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time autocorrelation.Online dictionary learning is followed to separate real signals from jamming slices.Under the learned representation,time-varying MISRJs are suppressed effectively.Both simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods.
基金Projected Supported by the National High Technology Research and Development Program of China(863 Program)(2015AA050203)National Talents Training Base for Basic Research and Teaching of Natural Science of China(J1103105)~~
文摘针对基于学习的人脸超分辨率算法噪点、伪影较多,且噪声鲁棒性较差的问题,提出一种基于在线字典学习的人脸超分辨率重建算法。以人脸图集作为训练图库,运用在线字典学习方法提高字典训练的精度。独立调整字典学习阶段的正则化参数λt和求解重建稀疏系数阶段的λr,以获取最优的超完备字典和稀疏系数用于图像重建。实验结果表明,目标图像峰值信噪比比同一类型的稀疏编码超分法平均提高了0.85 d B,结构相似性增加了0.013 3,有效地抑制了噪点和伪影。在含噪人脸图像应用中,噪声水平提高时,峰值信噪比下降相对较平缓,提升人脸超分效果的同时改善了算法的噪声鲁棒性。
