Tianhe Wang, Lin Liu, Jiaxi Zhao, Jing Zhang, Juanxiu Liu, Xiaohui Du, Ruqian Hao, Yi Liu
Quantitative phase imaging and measurement of surface topography and fluid dynamics for objects, especially for moving objects, is critical in various fields. Phase-shifting digital holography, as a highly accurate phase measurement technology applied for moving objects, is limited by some aspects, such as dynamic phase measurement, accuracy of phase shift and temporal phase sensitivity. In this study, we proposed a two-stage neural network (VY-Net) for one shot phase recovery. This Y-Net generates two holograms with specific phase shifts from a single-frame phase shifted hologram, then V-Net recovering the phase with the three holograms input. Simulation results prove that the proposed method can provide an alternative approach for systems of phase-shifting digital holography based on common-path configuration to realize rapid phase-shifted holograms acquisition and accurate phase measurement.
{"title":"A two-stage neural network recovering phase from a single-frame phase-shifted hologram","authors":"Tianhe Wang, Lin Liu, Jiaxi Zhao, Jing Zhang, Juanxiu Liu, Xiaohui Du, Ruqian Hao, Yi Liu","doi":"10.1117/12.3007260","DOIUrl":"https://doi.org/10.1117/12.3007260","url":null,"abstract":"Quantitative phase imaging and measurement of surface topography and fluid dynamics for objects, especially for moving objects, is critical in various fields. Phase-shifting digital holography, as a highly accurate phase measurement technology applied for moving objects, is limited by some aspects, such as dynamic phase measurement, accuracy of phase shift and temporal phase sensitivity. In this study, we proposed a two-stage neural network (VY-Net) for one shot phase recovery. This Y-Net generates two holograms with specific phase shifts from a single-frame phase shifted hologram, then V-Net recovering the phase with the three holograms input. Simulation results prove that the proposed method can provide an alternative approach for systems of phase-shifting digital holography based on common-path configuration to realize rapid phase-shifted holograms acquisition and accurate phase measurement.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"43 7","pages":"129420G - 129420G-10"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muao Shen, Mingyuan Zhang, Longfei Chang, Yingjun Li, Dejian Li
Based on the extremely narrow half-height width (FWHM) characteristics of ultrashort pulsed lasers, a DIC imaging technique that can realize picosecond time resolution is proposed by combining the traditional digital image correlation (DIC) technique with it. This method can solve the problems of blurring and dragging of scattering images caused by the sudden crack initiation and fast crack expansion in the fracture process of brittle materials. The crack opening displacement (COD) and the full-field displacement of the sample at the instant of cracking of brittle materials can also be obtained. In addition, the error in spatial resolution of the traditional DIC technique using a continuous light source can be greatly reduced by using this method. In this paper, this method is used to record the tip displacement field of a tuff sample containing a type I prefabricated crack under semicircular disk three-point bending (SCB) experimental conditions. The experimental results show that the recording of crack extension behavior on the order of picoseconds can be achieved using this method, and the key parameters of fracture of brittle materials are calculated more accurately.
基于超短脉冲激光的极窄半高宽（FWHM）特性，结合传统的数字图像相关（DIC）技术，提出了一种可实现皮秒级时间分辨率的 DIC 成像技术。这种方法可以解决脆性材料断裂过程中裂纹突然萌发和快速扩展所造成的散射图像模糊和拖影问题。同时，还可获得脆性材料开裂瞬间的裂纹开口位移（COD）和样品的全场位移。此外，使用这种方法还可以大大降低使用连续光源的传统 DIC 技术在空间分辨率上的误差。本文采用这种方法记录了含有 I 型预制裂纹的凝灰岩样品在半圆盘三点弯曲（SCB）实验条件下的顶端位移场。实验结果表明，使用该方法可以记录皮秒量级的裂纹扩展行为，并能更精确地计算脆性材料断裂的关键参数。
{"title":"Digital image correlation of brittle materials based on ultrashort pulse laser imaging","authors":"Muao Shen, Mingyuan Zhang, Longfei Chang, Yingjun Li, Dejian Li","doi":"10.1117/12.3005609","DOIUrl":"https://doi.org/10.1117/12.3005609","url":null,"abstract":"Based on the extremely narrow half-height width (FWHM) characteristics of ultrashort pulsed lasers, a DIC imaging technique that can realize picosecond time resolution is proposed by combining the traditional digital image correlation (DIC) technique with it. This method can solve the problems of blurring and dragging of scattering images caused by the sudden crack initiation and fast crack expansion in the fracture process of brittle materials. The crack opening displacement (COD) and the full-field displacement of the sample at the instant of cracking of brittle materials can also be obtained. In addition, the error in spatial resolution of the traditional DIC technique using a continuous light source can be greatly reduced by using this method. In this paper, this method is used to record the tip displacement field of a tuff sample containing a type I prefabricated crack under semicircular disk three-point bending (SCB) experimental conditions. The experimental results show that the recording of crack extension behavior on the order of picoseconds can be achieved using this method, and the key parameters of fracture of brittle materials are calculated more accurately.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"104 1","pages":"1294204 - 1294204-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical bottle beams exhibit a periodic cosine distribution along the axial direction. It has found extensive applications in areas such as optical trapping, optical tweezers, and guidance of biological cells. However, the current methods employed for generating such cosine light fields lack flexibility in controlling the period and phase, thus failing to achieve desired customization. This paper presents a novel approach for generating customized cosine light fields based on dual diffractionfree beams. The first step involves defining the desired cosine distribution light field. Subsequently, using the annular aperture method, multiple diffraction-free Bessel beams with different axial wave vectors are generated, and their superposition approximates the desired cosine light field. By modifying the phase and period of the desired cosine light field, adjustments can be made to the radius and width of the annular aperture, thus easily obtaining a customized cosine light field. The feasibility of the method was validated through rigorous mathematical analysis, and its effectiveness is demonstrated through experimental verification. This method is expected to propel further applications of optical bottle beams in areas including atomic trapping, optical modulation, and guidance of biological cells.
{"title":"Customized optical bottle beams based on dual diffraction-free beams","authors":"Tianle Li, Yuhao Li, Yuxuan Zhang, Xianlin Song","doi":"10.1117/12.3007263","DOIUrl":"https://doi.org/10.1117/12.3007263","url":null,"abstract":"Optical bottle beams exhibit a periodic cosine distribution along the axial direction. It has found extensive applications in areas such as optical trapping, optical tweezers, and guidance of biological cells. However, the current methods employed for generating such cosine light fields lack flexibility in controlling the period and phase, thus failing to achieve desired customization. This paper presents a novel approach for generating customized cosine light fields based on dual diffractionfree beams. The first step involves defining the desired cosine distribution light field. Subsequently, using the annular aperture method, multiple diffraction-free Bessel beams with different axial wave vectors are generated, and their superposition approximates the desired cosine light field. By modifying the phase and period of the desired cosine light field, adjustments can be made to the radius and width of the annular aperture, thus easily obtaining a customized cosine light field. The feasibility of the method was validated through rigorous mathematical analysis, and its effectiveness is demonstrated through experimental verification. This method is expected to propel further applications of optical bottle beams in areas including atomic trapping, optical modulation, and guidance of biological cells.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"22 2","pages":"129420H - 129420H-6"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhao Li, Wenkang Gong, Tianle Li, Jiaqing Dong, Xianlin Song
In recent years, significant progress has been made in deep learning-based image deblurring. These approaches utilize deep neural networks to learn the map between blurry and clear images or jointly learn the blurry kernel and clear image. They have demonstrated effectiveness in enhancing image quality, preserving details, and handling various types and degrees of blur. The objective of this study is to develop a defocus enhancement technique for real-world scenarios using score-based generative models. Stochastic differential equations (SDE) are employed to gradually introduce noise, thereby smoothing the data distribution towards a known prior distribution. The Score-Matching Langevin Dynamics (SMLD) model estimates the score for each noise scale, while Diffusion Models (DDPM) train the target model for score computation. This process constructs a score-based model capable of reversing the SDE over time. A predictor-corrector framework corrects the evolution of the reverse-time SDE, and the prior distribution is transformed back to the data distribution by removing the noise. By leveraging score-based generative models, accurate score estimation and sample generation are achieved using neural networks and numerical SDE solvers. This technique effectively restores clarity and details in defocused images, thereby enhancing overall image quality.
{"title":"Defocus-enhanced technique for real-world scenarios using generative models","authors":"Yuhao Li, Wenkang Gong, Tianle Li, Jiaqing Dong, Xianlin Song","doi":"10.1117/12.3007254","DOIUrl":"https://doi.org/10.1117/12.3007254","url":null,"abstract":"In recent years, significant progress has been made in deep learning-based image deblurring. These approaches utilize deep neural networks to learn the map between blurry and clear images or jointly learn the blurry kernel and clear image. They have demonstrated effectiveness in enhancing image quality, preserving details, and handling various types and degrees of blur. The objective of this study is to develop a defocus enhancement technique for real-world scenarios using score-based generative models. Stochastic differential equations (SDE) are employed to gradually introduce noise, thereby smoothing the data distribution towards a known prior distribution. The Score-Matching Langevin Dynamics (SMLD) model estimates the score for each noise scale, while Diffusion Models (DDPM) train the target model for score computation. This process constructs a score-based model capable of reversing the SDE over time. A predictor-corrector framework corrects the evolution of the reverse-time SDE, and the prior distribution is transformed back to the data distribution by removing the noise. By leveraging score-based generative models, accurate score estimation and sample generation are achieved using neural networks and numerical SDE solvers. This technique effectively restores clarity and details in defocused images, thereby enhancing overall image quality.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"41 9","pages":"129420F - 129420F-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tao Chen, Qiyang Chen, Zi Wang, Liming Zhu, Q. Feng, G. Lv
As we all know, the traditional compressed light field 3D display technology has the problems of limited 3D depth of field and low display brightness. In this paper, a hybrid compressed light field device based on polarization multiplexing is proposed, which combines multiplicative and superimposed compressed light field 3D display to improve the light intensity perceived by human eyes and enlarge the depth of field. In addition, when using high-brightness mini-leds, noise can appear at the edges of the reconstructed image. This is because non-negative tensor matrix (NTF) algorithm adopts hierarchical iteration, which is easy to fall into the local optimal solution, resulting in poor optimization effect of the edge part and noise. Then we introduce the stochastic gradient descent (SGD) algorithm which can better improve the problem of edge noise because all spatial light modulator pixel values are updated at the same time in the iteration process. In terms of perception indicators, NTF uses the mean square error coefficient, which cannot account for many nuances of human perception, resulting in iterative results that sometimes do not conform to the subjective perception of human eyes. In contrast, the loss function of SGD can be self-defined. This paper introduces the Learned Perceptual Image Patch Similarity, which is more in line with human perception. Through simulation and experiments, we verify the advantages of the proposed device and the effectiveness of the corresponding optimization algorithm.
众所周知，传统的压缩光场 3D 显示技术存在 3D 景深有限、显示亮度低等问题。本文提出了一种基于偏振复用技术的混合压缩光场设备，它结合了乘法和叠加压缩光场 3D 显示技术，提高了人眼感知的光强度，扩大了景深。此外，在使用高亮度微型 LED 时，重建图像的边缘会出现噪点。这是因为非负张量矩阵（NTF）算法采用分层迭代，容易陷入局部最优解，导致边缘部分优化效果不佳，出现噪点。随后，我们引入了随机梯度下降算法（SGD），该算法在迭代过程中所有空间光调制器像素值同时更新，因此能更好地改善边缘噪声问题。在感知指标方面，NTF 使用的是均方误差系数，无法考虑人类感知的许多细微差别，导致迭代结果有时不符合人眼的主观感知。相比之下，SGD 的损失函数可以自行定义。本文介绍了学习感知图像补丁相似性，它更符合人类的感知。通过仿真和实验，我们验证了所提设备的优势和相应优化算法的有效性。
{"title":"Hybrid compressed light field optimization algorithm based on stochastic gradient descent","authors":"Tao Chen, Qiyang Chen, Zi Wang, Liming Zhu, Q. Feng, G. Lv","doi":"10.1117/12.3007185","DOIUrl":"https://doi.org/10.1117/12.3007185","url":null,"abstract":"As we all know, the traditional compressed light field 3D display technology has the problems of limited 3D depth of field and low display brightness. In this paper, a hybrid compressed light field device based on polarization multiplexing is proposed, which combines multiplicative and superimposed compressed light field 3D display to improve the light intensity perceived by human eyes and enlarge the depth of field. In addition, when using high-brightness mini-leds, noise can appear at the edges of the reconstructed image. This is because non-negative tensor matrix (NTF) algorithm adopts hierarchical iteration, which is easy to fall into the local optimal solution, resulting in poor optimization effect of the edge part and noise. Then we introduce the stochastic gradient descent (SGD) algorithm which can better improve the problem of edge noise because all spatial light modulator pixel values are updated at the same time in the iteration process. In terms of perception indicators, NTF uses the mean square error coefficient, which cannot account for many nuances of human perception, resulting in iterative results that sometimes do not conform to the subjective perception of human eyes. In contrast, the loss function of SGD can be self-defined. This paper introduces the Learned Perceptual Image Patch Similarity, which is more in line with human perception. Through simulation and experiments, we verify the advantages of the proposed device and the effectiveness of the corresponding optimization algorithm.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"49 1","pages":"129420C - 129420C-6"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139180929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The binary defocusing technique is sensitive to the defocusing degree. The defocusing projection mechanism will introduce high-frequency harmonics at the inappropriate defocused level, leading to limitations in measurement accuracy and depth range. In this paper, a binary-focusing projection technique combining generative adversarial networks is proposed. First, the focusing binary patterns based on error diffusion are projected on the measured surface, and then the captured fringe patterns are input to generative adversarial networks, which achieves sinusoidal correction and optimization for both the focused region and the low-quality defocused region due to its strong image translation ability. Finally, 3D measurement is realized by a phase-shifting algorithm. Compared with the traditional binary defocusing technique, the proposed method is not limited by the defocusing degree and maintains the advantages of high-speed projection, so it can achieve a larger measured depth range and improve measurement accuracy. Simulation and experiments verify the performance of the proposed method.
{"title":"Large depth range dithered binary focusing fringe projection technique","authors":"Ji Tan, Xu Wang, Wenqing Su, Zhaoshui He","doi":"10.1117/12.3005606","DOIUrl":"https://doi.org/10.1117/12.3005606","url":null,"abstract":"The binary defocusing technique is sensitive to the defocusing degree. The defocusing projection mechanism will introduce high-frequency harmonics at the inappropriate defocused level, leading to limitations in measurement accuracy and depth range. In this paper, a binary-focusing projection technique combining generative adversarial networks is proposed. First, the focusing binary patterns based on error diffusion are projected on the measured surface, and then the captured fringe patterns are input to generative adversarial networks, which achieves sinusoidal correction and optimization for both the focused region and the low-quality defocused region due to its strong image translation ability. Finally, 3D measurement is realized by a phase-shifting algorithm. Compared with the traditional binary defocusing technique, the proposed method is not limited by the defocusing degree and maintains the advantages of high-speed projection, so it can achieve a larger measured depth range and improve measurement accuracy. Simulation and experiments verify the performance of the proposed method.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"13 3","pages":"1294203 - 1294203-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gang Yu, Zhenjie Shang, Xiameng Zhang, Rui Liu, Zhiyong Dai
Spark energy is one of the most important indicators for evaluating the performance of electric ignition systems. The development of electric ignition systems requires accurate measurement of spark energy to optimize system design parameters.The traditional oscilloscope test method calculates the spark energy by measuring the discharge electric energy. There is a serious energy conversion error, and the accurate measurement of spark energy cannot be realized. In this paper, based on radiation energy detection, a new method for direct measuring spark energy is reported. The multiband photodetector is used to conduct spatial sampling and spectral integration of the spark radiation energy. Then, using the high-speed response capability of the photodetector, high-precision measurement of spark energy is achieved by combining the time domain waveform of the spark pulse with the time integration of the spark radiation power. The experimental system can sample the spark radiant energy in 200nm~12,000nm spectral range by using 12 photodetectors, which is divided into four wavebands, and realize the direct test output of spark energy. The energy testing results show that the precision and stability of spark energy measurement are better than 5%. On the one hand, the method utilizes photodetectors to detect the radiation energy produced by electrical sparks and directly obtain the spark energy without requiring conversion between different forms of energy. Therefore, this approach offers higher measurement accuracy. On the other hand, the method takes advantage of the natural electromagnetic interference immunity of optical measurement techniques, which can effectively address the issue of strong electromagnetic interference caused by the electrical ignition system in oscilloscope methods. This can prevent distorted test results and ensure the ability to complete normal tests. Further studies show that the method can be used for accurate measurement of spark energy.
{"title":"A novel method for direct measurement of spark energy","authors":"Gang Yu, Zhenjie Shang, Xiameng Zhang, Rui Liu, Zhiyong Dai","doi":"10.1117/12.3007010","DOIUrl":"https://doi.org/10.1117/12.3007010","url":null,"abstract":"Spark energy is one of the most important indicators for evaluating the performance of electric ignition systems. The development of electric ignition systems requires accurate measurement of spark energy to optimize system design parameters.The traditional oscilloscope test method calculates the spark energy by measuring the discharge electric energy. There is a serious energy conversion error, and the accurate measurement of spark energy cannot be realized. In this paper, based on radiation energy detection, a new method for direct measuring spark energy is reported. The multiband photodetector is used to conduct spatial sampling and spectral integration of the spark radiation energy. Then, using the high-speed response capability of the photodetector, high-precision measurement of spark energy is achieved by combining the time domain waveform of the spark pulse with the time integration of the spark radiation power. The experimental system can sample the spark radiant energy in 200nm~12,000nm spectral range by using 12 photodetectors, which is divided into four wavebands, and realize the direct test output of spark energy. The energy testing results show that the precision and stability of spark energy measurement are better than 5%. On the one hand, the method utilizes photodetectors to detect the radiation energy produced by electrical sparks and directly obtain the spark energy without requiring conversion between different forms of energy. Therefore, this approach offers higher measurement accuracy. On the other hand, the method takes advantage of the natural electromagnetic interference immunity of optical measurement techniques, which can effectively address the issue of strong electromagnetic interference caused by the electrical ignition system in oscilloscope methods. This can prevent distorted test results and ensure the ability to complete normal tests. Further studies show that the method can be used for accurate measurement of spark energy.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"9 10","pages":"129420B - 129420B-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139180851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phase retrieval algorithms, such as the Wirtinger Flow (WF) algorithm, are widely used in various fields. As a nonconvex optimization algorithm for phase retrieval, WF is commonly employed in the reconstruction of holograms in holographic image projection. These types of algorithms typically involve two stages: an initialization stage and an iterative optimization stage. In the initialization stage, an initial value is provided, and a spectral method is used to calculate an approximate solution as the initial guess. The iterative optimization stage then utilizes the Wirtinger gradient to iteratively compute and converge the initial guess to a nearby real solution, thereby obtaining the global optimal solution. However, due to the random nature of the initial values, the computed results often exhibit significant instability. To address this issue, this paper proposes an approach based on a quadratic distribution for improving the stability of the results. In the initialization stage, the initial value is set as the quadratic distribution initial value. Then, the spectral method is applied again to calculate the initial guess. Since the quadratic distribution initial value is artificially assigned, it enhances the stability of the computed results. To validate this method, the paper applies the quadratic distribution initial value to both the initialization stage of the WF algorithm and the Truncated Amplitude Flow (TAF) algorithm. A comparison is made between the results obtained using random initial value and those obtained using the quadratic distribution initial values. The results demonstrate that compared to random initial values, the quadratic distribution initial values can achieve faster and equally accurate computation results with higher stability. Finally, this method is applied to simulation experiments of in-line digital holography, and the reconstruction results from the experiments further confirm the effectiveness of our approach.
{"title":"Research on the Wirtinger Flow algorithm based on quadratic distribution initial value","authors":"Zhenfei Xie, Xuelian Yu, Zhengxian Wang, Heng Li","doi":"10.1117/12.3005650","DOIUrl":"https://doi.org/10.1117/12.3005650","url":null,"abstract":"Phase retrieval algorithms, such as the Wirtinger Flow (WF) algorithm, are widely used in various fields. As a nonconvex optimization algorithm for phase retrieval, WF is commonly employed in the reconstruction of holograms in holographic image projection. These types of algorithms typically involve two stages: an initialization stage and an iterative optimization stage. In the initialization stage, an initial value is provided, and a spectral method is used to calculate an approximate solution as the initial guess. The iterative optimization stage then utilizes the Wirtinger gradient to iteratively compute and converge the initial guess to a nearby real solution, thereby obtaining the global optimal solution. However, due to the random nature of the initial values, the computed results often exhibit significant instability. To address this issue, this paper proposes an approach based on a quadratic distribution for improving the stability of the results. In the initialization stage, the initial value is set as the quadratic distribution initial value. Then, the spectral method is applied again to calculate the initial guess. Since the quadratic distribution initial value is artificially assigned, it enhances the stability of the computed results. To validate this method, the paper applies the quadratic distribution initial value to both the initialization stage of the WF algorithm and the Truncated Amplitude Flow (TAF) algorithm. A comparison is made between the results obtained using random initial value and those obtained using the quadratic distribution initial values. The results demonstrate that compared to random initial values, the quadratic distribution initial values can achieve faster and equally accurate computation results with higher stability. Finally, this method is applied to simulation experiments of in-line digital holography, and the reconstruction results from the experiments further confirm the effectiveness of our approach.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"78 1","pages":"1294205 - 1294205-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monocular imaging is constrained by limitations in the detection angle, making it susceptible to visual deceptions and making it difficult to obtain accurate shape and structural information of three-dimensional objects. The polarimetric characteristics of scattered light from objects contain information about surface roughness, texture, and structural differences. Therefore, introducing polarization measurements into monocular imaging systems holds significant potential. In this paper, based on polarized 3D imaging theory, the acquisition of surface normal information of objects is achieved by establishing the Stokes vector equation and relating it to Fresnel reflection and the Malus law. Rendering of normals and object surface directions is performed in the 3DsMax software. Ultimately, a monocular visual polarization imaging method is employed to correct the visual deception effect of objects with deceptive features. The results demonstrate that this method exhibits a certain recognition ability for three-dimensional objects composed of multiple planes with deceptive viewing angles.
{"title":"Research on visual deception recognition technology based on monocular polarization imaging","authors":"Zhong Lv, Yong Tan, Jianbo Wang, Ye Zhang, Hao Fang, Feng Chen, Zhaonan Huang, Chunxu Jiang, Jianwei Zhou","doi":"10.1117/12.3006232","DOIUrl":"https://doi.org/10.1117/12.3006232","url":null,"abstract":"Monocular imaging is constrained by limitations in the detection angle, making it susceptible to visual deceptions and making it difficult to obtain accurate shape and structural information of three-dimensional objects. The polarimetric characteristics of scattered light from objects contain information about surface roughness, texture, and structural differences. Therefore, introducing polarization measurements into monocular imaging systems holds significant potential. In this paper, based on polarized 3D imaging theory, the acquisition of surface normal information of objects is achieved by establishing the Stokes vector equation and relating it to Fresnel reflection and the Malus law. Rendering of normals and object surface directions is performed in the 3DsMax software. Ultimately, a monocular visual polarization imaging method is employed to correct the visual deception effect of objects with deceptive features. The results demonstrate that this method exhibits a certain recognition ability for three-dimensional objects composed of multiple planes with deceptive viewing angles.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"178 8","pages":"1294208 - 1294208-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xi Lin, Xiao-Shuai Hu, Tong-Yu Wang, Hanle Zhang, Yan Xing, Qiong Wang
Light field 3D display is a glasses-free 3D display that samples and reconstructs the light field guided by ray optics. To increase the density of the discrete viewpoints, parallax images in more than tens or even hundreds of directions should be sampled, which adds up to computation and slowdowns the generation speed of the 3D image source. In this paper, a fast generation method for 3D image source based on instancing camera rendering is proposed, which greatly optimizes the speed of the parallax image rendering process in light field 3D display. Experimental results reveal that the proposed method can generate the 4K and 8K light field 3D image sources at over 60 frames per second (fps) with viewpoints less than 160 and 80, respectively, performing at least 106% and 94% faster than the conventional non-instancing method.
{"title":"A real-time generation method for light field 3D image source based on instancing camera rendering","authors":"Xi Lin, Xiao-Shuai Hu, Tong-Yu Wang, Hanle Zhang, Yan Xing, Qiong Wang","doi":"10.1117/12.3006723","DOIUrl":"https://doi.org/10.1117/12.3006723","url":null,"abstract":"Light field 3D display is a glasses-free 3D display that samples and reconstructs the light field guided by ray optics. To increase the density of the discrete viewpoints, parallax images in more than tens or even hundreds of directions should be sampled, which adds up to computation and slowdowns the generation speed of the 3D image source. In this paper, a fast generation method for 3D image source based on instancing camera rendering is proposed, which greatly optimizes the speed of the parallax image rendering process in light field 3D display. Experimental results reveal that the proposed method can generate the 4K and 8K light field 3D image sources at over 60 frames per second (fps) with viewpoints less than 160 and 80, respectively, performing at least 106% and 94% faster than the conventional non-instancing method.","PeriodicalId":505225,"journal":{"name":"Advanced Imaging and Information Processing","volume":"17 1","pages":"1294209 - 1294209-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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