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Video super-resolution with phase-aided deformable alignment network

JOURNAL OF ELECTRONIC IMAGING 2020年第3期29卷

作者： Cai, Zhuojun Chen, Yaowu Tian, Xiang Jiang, Rongxin Zhejiang Univ Inst Adv Digital Technol & Instrument Hangzhou Peoples R China Zhejiang Univ State Key Lab Ind Control Technol Hangzhou Peoples R China Zhejiang Prov Key Lab Network Multimedia Technol Hangzhou Peoples R China Zhejiang Univ Minist Educ China Embedded Syst Engn Res Ctr Hangzhou Peoples R China

Video super-resolution (VSR) aims to restore a high-resolution frame from its corresponding reference frame and a series of neighboring frames in low resolution. Because of the displacement between the reference frame and each neighboring frame, which is caused by the motion of the camera or observed objects, VSR methods usually initially align the neighboring frames with the reference frame. However, the commonly used motion estimation and compensation methods highly depend on the predicted optical flow and they are affected by the lighting change. We propose a phase-aided deformable alignment network (PDAN) to alleviate the above problems. In PDAN, a phase-based method is introduced in the motion estimation subnetwork along with the traditional U-Net structure, which improves the restoration robustness in scenarios of lighting change. A deformable convolutional network is further adopted in the alignment subnetwork to enhance the alignment for objects with an irregular shape and motion distortion, which also avoids the dependence on explicit motion representation accuracy. Moreover, the reconstruction module is optimized for improved restoration. Extensive experiments conducted demonstrate that PDAN achieves state-of-the-art quantitative and qualitative performances. (C) 2020 SPIE and IS&T

关键词： deformable convolutional network neural network phase-based method video signal processing video super-resolution

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Full-field displacement measurement of long-span bridges using one camera and robust self-adaptive complex pyramid

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MECHANICAL SYSTEMS AND SIGNAL PROCESSING 2024年 215卷

作者： Wang, Yuchao Hu, Weihua Teng, Jun Xia, Yong Hong Kong Polytech Univ Dept Civil & Environm Engn Kowloon Hong Kong Peoples R China Harbin Inst Technol Shenzhen Dept Civil & Environm Engn Campus Shenzhen Univ Town Shenzhen Peoples R China Hong Kong Polytech Univ Joint Res Ctr Marine Infrastruct Kowloon Hong Kong Peoples R China

Full-field motion with a high spatial resolution can reflect the health state of long-span bridges. Traditional structural health monitoring (SHM) systems measure the structural displacement at sparse points only. Despite the development of various methods for obtaining high-resolution responses, they fail to estimate the multi-scale motions of real long-span bridges. A novel fullfield motion estimation method is proposed to directly measure the entire structural responses using one digital camera. In this approach, multi-scale motions of different components under unknown excitations are encoded in a complex pyramid. The parameters of the complex pyramid are determined by the localization index to record robust local phases at each measurement point. Two indices, namely, the spatial Laplacian of the phase and the amplitude value degradation index, are designed to adaptively estimate multi-scale displacements contained in the complex pyramid. The proposed method estimates the full-field displacements of a steel frame accurately in an experimental test. Moreover, the full-field displacement of the 1377-m long main span Tsing Ma Bridge is estimated using only one shot. Results suggest that the displacement estimated by the proposed method matches well with the GPS data and further visualizes the bridge mode shapes with a high resolution.

关键词： Full-field displacement phase-based method Long-span bridge Complex pyramid

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phase-based side information generation in distributed video coding

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MULTIMEDIA TOOLS AND APPLICATIONS 2022年第15期81卷 21295-21312页

作者： Chen, Hongjiang Wang, Wei Li, Jingjian Mo, Hong Chen, Jianhua Yunnan Univ Sch Informat Sci & Engn Kunming 650504 Yunnan Peoples R China

In distributed video coding, the quality of side information (SI) directly affects the final compression efficiency and rate-distortion performance. In the process of generating SI, many methods require accurate pixel matching and produce intermediate frames based on calculating motion vectors. As a result, they perform poorly in scenarios such as light changes, motion blur, and so on. In this case, phase-based frame interpolation for video (PBFI) is proved to be effective. And it has the advantages of simple implementation and easy parallelization. However, this method cannot get a good result when interpolating the video sequence of large motion. This paper proposes a phase-based SI generation method, which applies PBFI to distributed video coding and improves it from two aspects. (1) Move the high frequency information to the low frequency, reduce the proportion of the high frequency components, so that more frequency components can be interpolated in phase;(2) By correcting the phase difference again, more accurate phase shift information can be obtained when facing the video sequence of large motion. Simulation results show that the proposed method can effectively improve the quality of the generated SI. Thereby the overall performance of the distributed video coding system can be improved.

关键词： Distributed video coding Side information generation phase-based method Steerable pyramid decomposition

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Motion estimation from noisy data with unknown distributions using multi-frame phase-preserving denoising

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MECHANICAL SYSTEMS AND SIGNAL PROCESSING 2024年 206卷

作者： Wang, Yuchao Hu, Weihua Teng, Jun Xia, Yong Harbin Inst Technol Shenzhen Dept Civil & Environm Engn Campus Shenzhen Univ Town Shenzhen Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hong Kong Peoples R China Huazhong Univ Sci & Technol Sch Civil & Hydraul Engn Wuhan Hubei Peoples R China

phase-based motion estimation method is promising due to its high resolution and wide measurement range. Generally, noise exists in digital images and ruins the constant phase assumption of the same target among different frames. However, traditional image-denoising techniques do not consider the phase and result in inaccurate motion estimation. A novel phase-preserving denoising method considering multiple frames is proposed. In this approach, multi-scale and multi-orientation quadrature filters transform noisy images into complex pyramids to preserve the phase of the content. An instability indicator is designed to evaluate the relative noise intensity at each level of the complex pyramid among multiple frames. The threshold is then estimated to retain the phase of interest and reconstruct a denoised image with unknown noise distributions. Numerical and experimental examples demonstrate that the proposed method effectively preserves the phase of interest and decreases the error of the estimated motion, outperforming other typical denoising methods under various types of noise.

关键词： Motion estimation phase-based method Image denoising Complex pyramid

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Specific emitter identification based on Hilbert-Huang transform-based time-frequency-energy distribution features

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IET COMMUNICATIONS 2014年第13期8卷 2404-2412页

作者： Yuan, Yingjun Huang, Zhitao Wu, Hao Wang, Xiang Natl Univ Def Technol Coll Elect Sci & Engn Changsha 410073 Hunan Peoples R China Natl Univ Def Technol State Key Lab Complex Electromagnet Environm Effe Changsha 410073 Hunan Peoples R China

A novel specific emitter identification method based on transient communication signal's time-frequency-energy distribution obtained by Hilbert-Huang transform (HHT) is proposed. The transient starting point is detected using the phase-based method and the transient endpoint is detected using a self-adaptive threshold based on the HHT-based energy trajectory. Thirteen features that represent both overall and subtle transient characteristics are proposed to form a radio frequency (RF) fingerprint. The principal component analysis method is used to reduce the dimension of the feature vector and a support vector machine is used for classification. A signal acquisition system is designed to capture the signals from eight mobile phones to test the performance of the proposed method. Experimental results demonstrate that the method is effective and the proposed RF fingerprint can represent more subtle characteristics than the RF fingerprints based on instantaneous amplitude, phase, frequency and energy envelope. This method can be equally applicable for any wireless emitter to enhance the security of the wireless networks.

关键词： Hilbert transforms signal detection principal component analysis support vector machines mobile handsets telecommunication security mobile computing emitter identification Hilbert-Huang transform-based time-frequency-energy distribution features emitter identification method transient communication signal time-frequency-energy distribution phase-based method transient endpoint self-adaptive threshold HHT-based energy trajectory radio frequency fingerprint principal component analysis method feature support vector machine signal acquisition system mobile phones RF fingerprint RF fingerprints energy envelope frequency envelope wireless emitter wireless networks

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phase-based Modification Transfer for Video 14th

Phase-Based Modification Transfer for Video

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14th European Conference on Computer Vision (ECCV)

作者： Meyer, Simone Sorkine-Hornung, Alexander Gross, Markus ETH Dept Comp Sci Zurich Switzerland Disney Res Zurich Switzerland

ISBN: (纸本)9783319464879;9783319464862

We present a novel phase-based method for propagating modifications of one video frame to an entire sequence. Instead of computing accurate pixel correspondences between frames, e.g. extracting sparse features or optical flow, we use the assumption that small motion can be represented as the phase shift of individual pixels. In order to successfully apply this idea to transferring image edits, we propose a correction algorithm, which adapts the phase shift as well as the amplitude of the modified images. As our algorithm avoids expensive global optimization and all computational steps are performed per-pixel, it allows for a simple and efficient implementation. We evaluate the flexibility of the approach by applying it to various types of image modifications, ranging from compositing and colorization to image filters.

关键词： phase-based method Video processing Edit propagation

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Segmented Optimal Design of Ballistic Trajectory of Gliding Extended Range Projectile Subjected to Multiple Constraints

Segmented Optimal Design of Ballistic Trajectory of Gliding ...

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International Conference on Robotics and Automation Sciences (ICRAS)

作者： Ge, Zhilei Wang, Yanni Huang, Yan Liu, Suyun Northwestern Polytech Univ Sch Astronaut Xian Shaanxi Peoples R China

ISBN: (纸本)9781538639955

Gliding extended range projectile is restricted by such conditions as the speed, the engine thrust force, the engine work time and the impact point speed inclination when attaining the longest range. To simplify the problem and acquire a well-designed trajectory, a phase-based method for optimizing the overall trajectory is presented. The overall trajectory is divided into the boosted phase, the cruise phase, the gliding phase and the terminal guidance phase. After overall consideration of the constraints and index requirements of all phases, different methods were used to optimize each phase, including the optimal angle of firing design, the design for minimizing energy loss, the optimal glide design and the terminal phase dive method, so as to optimize the overall trajectory. Simulation results show that the designed trajectory can meet the design requirements for multiple constraints and achieve the longest extended range as well as 10km similar to 70km whole range coverage. The conclusion is of certain significance in developing rocket projectiles.

关键词： extended range projectile minimized energy loss trajectory multiple constrains phase-based method

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FRAME INTERPOLATION USING phase AND AMPLITUDE FEATURE PYRAMIDS 26

FRAME INTERPOLATION USING PHASE AND AMPLITUDE FEATURE PYRAMI...

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26th IEEE International Conference on Image Processing (ICIP)

作者： Zhou, Lunan Chen, Yaowu Tian, Xiang Jiang, Rongxin Zhejiang Univ Zhejiang Prov Key Lab Network Multimedia Technol Hangzhou Peoples R China Zhejiang Univ Minist Educ Embedded Syst Engn Res Ctr Hangzhou Peoples R China Zhejiang Univ State Key Lab Ind Control Technol Hangzhou Peoples R China

ISBN: (纸本)9781538662496

This paper presents a compact neural network for video frame interpolation using phase and amplitude feature pyramids. We design a set of one-dimensional separable complex Gabor filters to extract phase and amplitude feature pyramids for each input image, which is efficient and effective for motion representation. The pyramids are fused and fed into a decoder network to estimate bi-directional optical flow. The interpolated frame is refined by a context-aware synthesis module. We train our model on quintets of frames using motion linear regularization. The proposed network contains much fewer parameters than state-of-the-art approaches. The experiments show that our method outperforms the competing methods. Moreover, our method achieves marked visual improvement in the challenging scenario with lighting changes.

关键词： Gabor filtering frame interpolation phase-based method neural network

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phase-based frame rate up-conversion for depth video

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JOURNAL OF ELECTRONIC IMAGING 2018年第4期27卷 043036-043036页

作者： Zhou, Lunan Sun, Rui Tian, Xiang Chen, Yaowu Zhejiang Univ Inst Adv Digital Technol & Instrument Zhejiang Prov Key Lab Network Multimedia Technol Hangzhou Zhejiang Peoples R China Sichuan Univ Coll Phys Sci & Technol Chengdu Sichuan Peoples R China Zhejiang Univ Embedded Syst Engn Res Ctr State Key Lab Ind Control Technol Minist Educ Hangzhou Zhejiang Peoples R China

Due to the limits of frame rate sampling like time-of-flight and transmission bandwidth constraints of depth video, depth frame rate up-conversion is imperative. Most researches interpolate the depth frames using the motion information of the texture images, which require well-rectified images. They usually find dense correspondences to synthesize an in-between frame. Estimating the correspondences is sensitive to occlusion, disocclusion, and color or luminance changes. This paper proposes a phase-based method to interpolate depth frames without explicitly finding correspondences. Combining top-down phase difference preservation and bottom-up phase difference correction, varying amounts of motions are well modeled in a complex-steerable pyramid decomposition. The pixel amplitude is also shifted and interpolated based on the phase information. Finally, a depth value correction is employed to correct the inaccurate depth value. Experimental results show that the depth video interpolated by our proposed approach provides better subjective and objective qualities. (C) 2018 SPIE and IS&T

关键词： depth video frame interpolation view synthesis phase-based method video processing

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phase-based motion estimation in complex environments using the illumination-invariant log-Gabor filter

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MECHANICAL SYSTEMS AND SIGNAL PROCESSING 2023年 186卷

作者： Wang, Yuchao Hu, Weihua Teng, Jun Xia, Yong Campus Shenzhen Univ Town Harbin Inst Technol Shenzhen Dept Civil & Environm Engn Shenzhen Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Kowloon Hong Kong Peoples R China

The phase-based motion estimation method is promising because the phase is sensitive to the motion information embedded in the pixel values. Unfortunately, complex environments such as extra textures and illumination changes exist in practice, whereas their effects have not been studied. This study theoretically discovers that the large spatial size and DC component of the filter adversely affect the performance of the motion estimation method under complex environments. The traditional method adopting the Gabor filter with a large bandwidth may suppress extra textures while cause a significant drift in the estimated motion due to the negative frequency and DC components. To tackle this, a log-Gabor-based new motion estimation method is proposed, in which the log-Gabor filter intrinsically without the DC and negative frequency components can extract the local phase and filter out the illumination change. A localization index based on the amplitude map is designed to determine the optimal parameters of the logGabor filter and maximize its spatial localization capability. Numerical and experimental examples demonstrate that the proposed method outperforms the traditional Gabor filter in motion estimation under the complex environment.

关键词： Motion estimation phase-based method Log-Gabor filter Complex environment

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