The pseudo-overlapped imaging system was proposed to resolve the fundamental trade-off between a large field of view (FOV) and high spatial resolution in 3D digital image correlation (3D-DIC). To overcome the limitations of such systems in synchronous acquisition, this paper introduces PONet, a deep neural network designed to separate complex nonlinear overlapped images from different FOVs on the sensor. The network incorporates Atrous Spatial Pyramid Pooling (ASPP) to enhance multi-scale feature extraction, and employs a dual-output head architecture to ensure independent and clear reconstruction of both sub-views. Integrated into the imaging setup, PONet enables an end-to-end synchronous acquisition and back-end decoupling framework, allowing single-shot measurements as well as measurements of large specimens spanning both fields of view. Experimental results demonstrate that the reconstructed 3D displacement fields show good agreement with benchmark data. A continuous full-field displacement map was successfully generated by stitching these fields together.

Two-dimensional digital image correlation (2D-DIG) is indispensable for in-plane deformation measurement owing to its simple configuration and high computational efficiency. However, its measurement accuracy is severely compromised by the defocus blur effect and virtual deformation induced by out-of-plane motion. Existing compensation methods typically address only one of these two issues and tend to fail when severe defocus prevents correlation computation entirely. To address this challenge, this study introduces a compensation method based on an electrically tunable lens (ETL). The mechanism by which the ETL eliminates the influence of out-of-plane displacement and achieves autofocus is first analyzed. Technically, a climbing search algorithm based on DIG measurement strategy rapidly modulates the ETL focal length by targeting stripe spacing, maintaining both image clarity and constant magnification during the image acquisition stage to compensate for defocus blur effect and virtual deformation caused by out-of-plane motion. Multiple experimental validations confirm the effectiveness of this approach. This approach reduces substantial virtual strain to noise levels while simultaneously resolving defocus issues in measurements. This comprehensive compensation fundamentally improves the quality and reliability of the raw speckle images, thereby providing a solid foundation for accurate deformation measurement. The ETL-based method effectively expands the application potential of 2D-DIG for characterizing flexible materials and holds promise for future extension to microscopic deformations. (c) 2026 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

An effective calibration method for a pseudo-overlapped imaging system was investigated based on pseudo-overlapped imaging. To address the restriction between field-of-view (FOV) enlargement and spatial resolution enhancement in optical monitoring, a multiview digital image correlation system based on pseudo-overlapped imaging was developed to reconstruct large movements of relatively small objects. Using a specially designed chessboard pattern, the intrinsic and extrinsic parameters of the four virtual cameras were calibrated without the need for overlapped field, which can be used in discontinuous FOVs. Consequently, the world coordinate systems of the different FOVs were reconstructed and unified. The results show that the calibration accuracy, with different stitching areas, had an error of 0.05 pixels, comparable to that of traditional multicamera systems. The effectiveness of the calibration method and the feasibility of the multiview measurement system based on overlapped imaging were validated through cylindrical translation experiments and high-speed dynamic experiments involving a ball.

Objective The simultaneous acquisition of full-field stress and strain distributions during material deformation is essential for understanding the mechanical behavior of transparent structures.Traditional optical measurement techniques frequently encounter challenges in synchronously acquiring stress and strain data due to incompatibilities in their information carriers.Conventional optical methods typically employ separate imaging techniques for each physical quantity,creating complexities in combining these measurements.To address this limitation,this study presents an innovative approach that integrates photoelasticity and digital image correlation(DIC),utilizing the spectral separation between fluorescent speckle patterns and photoelastic fringes.This integration enables the synchronized measurement of strain and stress fields using a single imaging system,facilitating more efficient and precise analysis of material behavior under stress. Methods In this study,a transparent polymethyl methacrylate(PMMA)specimen was selected as the experimental sample,offering suitable properties for observing both photoelastic and fluorescent phenomena.The specimen surface was coated with blue fluorescent speckle and illuminated using UV light to generate fluorescent speckles for DIC analysis.Red monochromatic light was utilized to produce photoelastic fringes through birefringence.A single 3CCD camera with spectral separation capabilities simultaneously captured the red channel(photoelastic fringes)and blue channel(fluorescent speckles).To obtain full-field stress information from the photoelastic fringe patterns,a six-step phase-shifting method was implemented,and the wrapped phase data underwent processing using the Flynn unwrapping algorithm.Concurrently,full-field displacement and strain data were computed via 2D-DIC on the speckle images,enabling deformation measurement under various load conditions.A four-point bending test was implemented to simulate mechanical loading,facilitating evaluation of the system's effectiveness in synchronous stress and strain measurement. Results and Discussions The experimental results demonstrate the viability and effectiveness of the proposed method in simultaneously obtaining full-field distributions of stress and strain during material deformation.The strain fields determined through DIC aligned with the theoretical deformation patterns of four-point bending,with strain distributions showing clear tension-compression symmetry,consistent with the expected mechanical behavior of the PMMA specimen under bending stress.Furthermore,the phase maps derived from photoelastic fringes demonstrated appropriate symmetry,validating the accuracy of stress measurements.Significantly,principal strain difference and principal stress difference exhibited similar spatial patterns,indicating the method's capability to provide consistent and reliable results in simultaneous mechanical characterization.Although minor spectral crosstalk was detected between red and blue channels,resulting in slight interference,the impact on overall image quality remained negligible and did not compromise measurement reliability.However,while the method offers substantial advantages in static or quasi-static testing conditions,the requirement for sequential image acquisition in phase-shifting constrains its applicability under dynamic loading conditions.This limitation stems from the necessity to capture multiple images at different phase shifts,presenting challenges for high-speed,real-time measurements. Conclusions This study presents an optical measurement system integrating DIC and photoelasticity through fluorescent speckles and a 3CCD camera.The system facilitates synchronous acquisition of stress and strain data,offering a practical approach to material testing while simplifying experimental preparation.The method demonstrates significant potential for analyzing transparent structures,where simultaneous measurement of stress and strain is crucial for comprehensive understanding of material behavior under load.Future research will focus on enhancing the system's capacity for dynamic measurements by incorporating phase retrieval techniques suitable for high-speed testing.This advancement would expand its applicability for real-time monitoring of material deformation under dynamic loading conditions.These improvements could establish the system as a valuable tool in materials science research.

The storage and transmission of videos at high spatial resolution remain a great challenge in image-based optical techniques. The uncertainty of digital image correlation (DIC) was assessed following speckle video compression under High Efficiency Video Coding (HEVC/H.265). First, the evaluation criterion for the DIC accuracy affected by compression was provided. The stability of H.265 video compression in DIC was studied considering different compressed frames under different target quantization parameters (QPs) and compression ratios (CRs). The deformation uncertainty of the DIC itself as affected by H.265 video compression was further investigated through uniform translation and non-uniform sinusoidal deformation performance. Moreover, the optimized digital speckle pattern (DSP) was re-evaluated considering video compression-induced uncertainty. DSPs with parameters of different diameters and randomness were compressed using various QPs and CRs. In addition, DSP evaluation was performed under both translation and non-homogeneous deformation conditions. The feasibility of the re-optimized DSP under H.265 video compression was validated using a defective bending beam, and DSP videos with a speckle size of 8 pixels reached a high CR within an acceptable margin of error.

The restriction of the field of view (FOV) enlargement and spatial resolution increase during optical monitoring was investigated. Traditional optical instruments usually have a fixed FOV in one test; thus, they have low accuracy for small samples under large motions/deformations. To improve the spatial resolution in a relatively large FOV of an optical instrument, a multiple-view 3D digital image correlation (3D-DIC) method based on pseudo-overlapped imaging is proposed. Using a set of optical components, pseudo-overlapped imaging can image two FOVs with the same camera, which converts one pair of cameras to four virtual cameras. Each virtual camera has the same whole pixels. Therefore, compared with the conventional 3D-DIC system, the proposed method simultaneously enlarges FOVs and increases spatial resolutions by two times. The efficiency, accuracy, and feasibility of the technique were validated through experiments.

Objective Full-field thickness-direction strain measurement within a large deformation range is of significance for mechanical performance testing of materials. Based on a multispectral digital image correlation compact setup, we measure the full-field thickness-direction strain of transparent hyperelastic materials. By pre- fabricating two different fluorescent speckle patterns on the front and back surfaces of the transparent sample and combining them with an auxiliary prism and a single color camera assembly, synchronous observation of thickness deformation on one side of the sample is achieved by employing four virtual cameras. To accurately calculate thickness deformation, we firstly adopt refraction distortion correction based on Snell law and the positional relations of the four virtual cameras to reconstruct and unify the surface topography coordinates of the front and back surfaces of the sample. Furthermore, by utilizing the inverse distance weighting interpolation method, the frontal and back surface three-dimensional scattered data in a local coordinate system in any loading condition is interpolated to generate uniformly and symmetrically distributed interpolation points, establishing a one-to-one correspondence between points on the front and back surfaces. Finally, strain within the thickness is calculated point by point to determine the distribution of full-field thickness-direction deformation. This method is successfully applied to the large deformation stretching experiment of an upconversion fluorescence-responsive disulfide crosslinked polyurethane (DSPU) elastomer. Methods We research a single-camera multispectral digital image correlation system. First, as shown in Fig. 1(a), the object's image is projected onto the left and right sides of the sensor by adjusting the position and angle of the outer flat mirror. Different colored fluorescence speckle patterns are applied to the front and back surfaces of the transparent sample, and two corresponding color channels of the 3CCD camera are adopted to record the images of the two relative surfaces, thus achieving the operation of a four-virtual-camera stereo perspective imaging system. Then, we leverage the 3D-DIC algorithm to reconstruct the front and back surfaces of the 3D object. Furthermore, for the convenience of statistical and computational analysis of thickness information, as shown in Fig. 4, we transform the 3D data in the global coordinate system into a new local coordinate system. In the new coordinate system, to determine the one-to-one correspondence between the point cloud coordinates of the front and back surfaces, we employ a 3D discrete data interpolation method. During the interpolation, we adopt the same parameters to generate uniformly and symmetrically distributed interpolation points. By performing statistical analysis and calculations on all interpolation point coordinates, we obtain the full-field thickness-direction strain distribution of the material. Results and Discussions We characterize the uniform and non-uniform full-field thickness of transparent thin plates and semicylinders. The results show that the system has excellent accuracy, with a relative error of less than 1%. By carrying out uniaxial tensile experiments, we obtain the full-field thickness-direction strain distribution of an upconversion fluorescence-responsive DSPU elastomer and establish the corresponding strain variation trend at calculation points. The feasibility of a single-camera multispectral digital image correlation compact device for measuring full-field thickness-direction strain in transparent hyperelastic materials is verified. As shown in Fig. 8, the material's thickness undergoes a maximum variation of 62% before rupture, and throughout the process, the thickness-direction strain is uniformly distributed without distinct necking features. As shown in Fig. 9, the full-field thickness-direction strain curve displays nonlinearity, including an elastic stage and a hardening stage. In the elastic stage, the thickness-direction strain rapidly increases with the rising load, while in the hardening stage, when the load reaches a certain value, the material starts to harden, which results in lower growth of thickness-direction strain and ultimately failure. Conclusions We propose a single-camera multispectral three-dimensional digital image correlation measurement device, which features low cost, compact design, and easy implementation. The relative error in thickness measurement accuracy verification experiments is less than 1%. By conducting uniaxial tensile experiments, we obtain the full-field thickness-direction strain distribution characteristics of DSPU elastomers. Although local issues such as internal material defects and defocusing of back surface speckles lead to slight non-uniformity in the overall strain distribution, the proposed compact multispectral digital image correlation device overcomes the limitation of traditional 3D-DIC techniques that can only provide the deformation information of a single surface. Additionally, by combining fluorescent speckles and multispectral imaging technologies, low-cost and high-precision full-field thickness-direction deformation measurement is achieved to provide accurate and reliable thickness deformation information for transparent hyperelastic materials. Meanwhile, since the system utilizes a single camera and prism combination imaging, the spatial resolution of sampled images is somewhat reduced. Therefore, optical system improvements are required to enhance imaging resolution.

To study the compressive properties of an elastomeric porous cylinder, a 360° 3D digital image correlation (DIC) system is proposed. This compact vibration isolation table system captures different segments of the object from four different angles and fields of view, enabling a comprehensive measurement of the full surface of the object. To increase the stitching quality, a coarse–fine coordinate matching method is presented. First, a three-dimensional rigid body calibration auxiliary block is employed to track motion trajectory, which enables preliminary matching of four 3D DIC sub-systems. Subsequently, scattered speckle information characteristics guide fine matching. The accuracy of the 360° 3D DIC system is verified through a three-dimensional shape measurement conducted on a cylindrical shell, and the maximum relative error of the shell’s diameter is 0.52%. A thorough investigation of the 3D compressive displacements and strains exerted on the full surface of an elastomeric porous cylinder are investigated. The results demonstrate the robustness of the proposed 360° measuring system on calculating images with voids and indicate a negative Poisson’s ratio of periodically cylindrical porous structures.

Accurate quantification of the true stress-strain curve over an extensive strain range is pivotal for elucidating material mechanical properties and simulating non-linear plastic deformation. A novel experimental approach was developed to directly measure true stress-strain behavior in transparent materials. Our setup featured a single 3CCD camera and mirrors, capturing images of both specimen surfaces with bicolored fluorescent speckle patterns. Initially, we determined and corrected the specimen's refractive index using a point-by-point least squares method. Subsequently, we used multispectral dual 3D digital image correlation (DIC) to reconstruct surface profiles and correct refractive distortions. This allowed precise computation of the deformed cross-sectional area over an expansive strain range. True stress was calculated from the measured engineering stress and computed deformed area. Validity was confirmed by deforming a fluorescent elastomer, and results aligned with the theoretical predictions. This compact experimental setup effectively evaluates true stress-strain relationships in transparent materials under extensive deformation.

We propose a novel hybrid FPP-DIC technique to measure an object’s shape and deformation in 3D simultaneously by using a single 3CCD color camera, which captures the blue fringe patterns and red fluorescent speckles within the same image. Firstly, red fluorescent speckles were painted on the surface of the specimen. Subsequently, 12 computer-generated blue fringe patterns with a black background were projected onto the surface of the specimen using a DLP projector. Finally, both the reference and deformed images with three different frequencies and four shifted phases were captured using a 3CCD camera. This technique employed a three-chip configuration in which red–green–blue chips were discretely integrated in the 3CCD color camera sensor, rendering independent capture of RGB information possible. Measurement of out-of-plane displacement was carried out through the implementation of Fringe Projection Profilometry (FPP), whereas the in-plane displacement was evaluated using a 2D Digital Image Correlation (DIC) method by leveraging a telecentric-lens-based optical system. In comparison to the traditional FPP-DIC hybrid methodology, the present approach showed a lower incidence of crosstalk between the fringe patterns and speckle patterns while also offering a corrective for the coupling of the in-plane displacement and out-of-plane displacement. Experimental results for the in-plane cantilever beam and out-of-plane disk comparisons with the traditional 3D-DIC method indicated that the maximum discrepancy obtained between FPP-DIC and 3D-DIC was 0.7 μm and 0.034 mm with different magnifications, respectively, validating the effectiveness and precision of the novel proposed FPP-DIC method.

Three-dimensional (3D) digital image correlation (DIC) based on fluorescent speckle pattern is becoming popular for measuring 3D profiles and deformations. However, the simultaneous monitoring of both the front and rear surfaces remains challenging due to the different refractive indexes of light in different media. In this study, we utilized a multispectral 3D DIC method using fluorescent speckle patterns and a 3CCD camera for the front and rear surfaces measurement of transparent objects. Fluorescent speckle patterns excited red or blue light were sprayed on the interested surfaces before measurement. Then, the red channel and blue channel sub-systems of a virtual 3D DIC system with a 3CCD camera were used to simultaneously capture both the front and back surfaces, respectively. To unify the sub coordinate systems of different channels, a calibration model of the 3CCD camera considering the sensor designed optical path difference (OPD) was proposed. Furthermore, profile reconstruction was corrected based on Snell's law to eliminate the refractive distortion caused by the different refractive indexes. The experimental results of transparent flat and curved objects showed that the accuracy of this method was significantly improved.

During insect flight, some overlapping phenomena such as torsion, bending, and warping will appear in the wings, which makes the wings shielded from each other and thus leads to hard discrimination of the flight attitude by traditional optical measurement. To realize the dynamic measurement of mutual occlusion of transparent membranous wings, this paper proposed a three-dimensional (3D) digital image correlation method based on fluorescence polarization imaging to measure the 3D full-field deformation of multi-wing structures. According to the principle of polarization imaging, the 3D morphology of a monochromatic wing can be measured by a single polarization camera in the presence of a splitting optical path integrating mirrors, polarizers and a splitting prism. Depending on the spectral characteristics of fluorescent speckles, different fluorescent speckles were fabricated on different wings that were shielded from each other, and a band-pass filter was used to separate the fluorescent speckles of specific spectra on them, which enabled the independent imaging and synchronous measurement of multiple wings. Firstly, the measurement experiments of the relative surface topography and deformation of the sheet with equal thickness were carried out to calibrate the measurement accuracy of multiple mutually shielded surfaces. Further, the different overlapping forms of insect wings (cicadas) were measured, and the 3D profile of any mutually shielded wings was given to verify the feasibility of the measurement method.

Fluorescent digital image correlation (DIC) is becoming popular for measuring 3D profiles and deformations in external surfaces. However, the simultaneous monitoring of interior layers is highly challenging due to the penetrability and refraction of light using monochromatic fluorescence. We propose a color fluorescent speckle pattern (CFSP) method for measuring the internal displacement of transparent objects based on multispectral stereo-DIC and refractive index correction. During sample fabrication, fluorescent speckle patterns exciting different colors are fabricated on both the surface and interior layers of objects. A virtual color stereo-DIC system is utilized to capture the CFSP on the surface and interior layers simultaneously from two different perspectives. Different color channels are practically equivalent to synchronized monochrome vision systems, having separate CFSP in external and internal measurements. In multispectral stereo-DIC calculation, the external surface is initially reconstructed through one channel of the system even if the surface is non-planar. Based on Snell's law and the CFSP method, the internal layer is then reconstructed and corrected by establishing the geometry of the refractive stereo-DIC through another channel. The relative error of the thickness between two planar layers was proved to decrease from 33.4% to 0.7% after refractive index correction. Further experimental results validate the efficacy of this method for correcting the profile of the non-planar arc profile and determining the internal deformations of disc materials.

This study analyzes the function of different muscles during arm wrestling and proposes a method to analyze the optimal forearm angle for professional arm wrestlers.We built a professional arm-wrestling platform to measure the shape and deformation of the skin at the biceps brachii of a volunteer in vivo during arm wrestling.We observed the banding phenomenon of arm skin strain during muscle contrac-tion and developed a model to evaluate the moment provided by the biceps brachii.According to this model,the strain field of the area of interest on the skin was measured,and the forearm angles most favorable and unfavorable to the work of the biceps brachii were analyzed.This study demonstrates the considerable potential of applying DIC and its extension method to the in vivo measurement of human skin and facilitates the use of the in vivo measurement of skin deformation in various sports in the fu-ture.

Simultaneous monitoring of multiple fields of view (FOVs) by multiscale stereo-digital image correlation (stereo-DIC) can quantify the deformation of a material when localized phenomena occur within a larger FOV or moving object. In multiscale deformation measurement via stereo-DIC, optimization of the digital speckle patterns (DSPs) is essential to achieve high accuracy and efficiency. This work optimizes and fabricates multispectral DSPs used for multiple scales. First, an optimization of the DSP for two FOVs is achieved using both spatial modulation and specified spectra. A spatially modulated DSP is compared with two spectral DSPs achieved by visible and ultraviolet-excited blue light. Then, a spatially modulated visible DSP fabricated by an ultraviolet printer overlaid with an ultraviolet-excited blue DSP fabricated by a photosensitive seal is designed for multiscale stereo-DIC measurements of three FOVs. Experiments were performed to illustrate the functionality and utility of this multiscale DSP. Such experimental analyses can supply adequate full-field data to validate localized or kinetic mechanical behavior.

Simultaneous monitoring of overlapped multi-wing structure by stereo-digital image correlation (stereo-DIC) may be used to quantify insect motion and deformation. We propose a dual stereo-DIC system based on multispectral imaging with a polarization RGB camera. Different fluorescent speckle patterns were fabricated on wings, which emit red and blue spectra under ultraviolet light that were imaged and separated using a polarization RGB camera and auxiliary optical splitting components. The resulting dual stereo-DIC system was validated through translation experiments with transparent sheets and reconstructed overlapped insect wings (cicadas). Dynamic measurements of the Ruban artificial flier indicate the efficacy of this approach to determining real insect flight behavior.

With the increase in digital image correlation (DIC) applications, the computational efficiency of DIC is becoming increasingly important. In previous studies, real-time DIC was realized with a relatively small subset. However, a small subset does not always include sufficient gray gradient information. In this paper, a pixel selection strategy is proposed to improve the computational efficiency of DIC further, allowing a real-time deformation measurement with a large subset. Within the subset, zero weight is assigned to unreliable pixels as a way of pursuing maximum efficiency. The modulus of the local intensity gradient vector of each pixel in the reference image is used as the criterion for reliability. Numerical and real experiments conducted to validate the feasibility and effectiveness of the strategy showed that the computational speed of DIC could be improved about 2 times.

Understanding the biomechanical behavior of dentin hard tissue with fluid-filled dentin tubules and hydrated matrices is essential for studying this functionally graded biological composite. The stereo-digital image correlation technique with an adaptive high-magnification field of view (FOV) for fully hydrated biological tissue measurement was investigated. The adaptive magnification is controlled by the length of extension tubes. To determine both the unbound water loss induced and load-induced three-dimensional (3D) deformation of dentin hard tissue from a fully hydrated state to a non-hydrated condition, samples of dentin blocks and half teeth in sagittal sections were studied for a period of 2 h in situ over varied speckle patterns. The effects of speckles on water evaporation, camera pre-heating, and measurement accuracy in the wet, curved and long-term measurement were analyzed. The elastic modulus and Poisson’s ratio of both dentin and pulp in response to unbound water evaporation were measured. With the unbound water loss, the mean values of the elastic modulus generally increased from ∼8 GPa to ∼10 GPa in pulp region and from ∼10 GPa to ∼12 GPa in dentin region. The mean values of the Poisson’s ratio increased both in pulp and in dentin. Poisson’s ratio in the dentin regions (∼0.3) were generally smaller than those in the pulp regions (even can reach 0.6), irrespective of the partial dehydration time. Further analysis of the full-field deformation results provided insight into the unbound water-induced regional deformations and mechanical changes in human dentin. It’s found that the unbound water loss induced deformations were more prominent when compared to load induced deformations.

INTRODUCTION:This study evaluated free water loss-induced residual strain with and without axial compressive loading and assessed the mechanical effect of cyclic loading in fully hydrated and partially dehydrated root dentin.METHODS:Root dentin sections prepared from freshly extracted human premolars were used. Customized 3-dimensional digital image correlation was used to qualitatively and quantitatively analyze the residual strain induced by 2 hours of free water loss in different regions of root dentin. Residual strain in partially dehydrated root dentin during axial compressive loading was also analyzed using 3-dimensional digital image correlation. The effect of cyclic loading on load to fracture in fully hydrated and partially dehydrated dentin and their fractography were analyzed using micro-computed tomographic imaging.RESULTS:Free water loss resulted in a heterogeneous distribution of residual strain and an overall formation of residual compressive strain with areas of tensile strain localized to the root canal and outer dentin. More residual compressive strain was observed in the apical dentin compared with the cervical dentin (P < .05), and more residual shear strain was observed in outer dentin compared with inner dentin (P < .05). Axial loading resulted in an increase in the load-induced compressive strain in the direction perpendicular to dentinal tubules (P < .05). Fully hydrated roots displayed a higher mean (P < .05) and median (P < .05) number of cycles to fracture with microcracks characteristic of toughness.CONCLUSIONS:After free water loss, root dentin displayed an increased formation of heterogenous residual strain, which resulted in increased axial compressive load-induced strain and a decreased resistance to fatigue failure. The effect of free water loss in the loss of mechanical integrity of root-filled teeth needs further investigation.

Digital image correlation (DIC) is a well-known technique for non-contact, non-destructive, full-field deformation measurement in experimental solid mechanics. Although DIC has been widely used in science and engineering, the resolution of strain measurement with DIC is limited by imaging resolution and is much lower than that obtained with a strain gauge. To achieve a breakthrough in strain measurement using DIC, a camera array-based DIC method is proposed herein for high-resolution strain measurement. Twenty-five industrial cameras were assembled into a plane array, with each camera capturing a part of the specimen. A novel calibration-based image stitching method is proposed and was applied to these images and their corresponding displacement fields. The strain field was then calculated based on the stitched displacement fields. The use of the camera array greatly improved the measurement spatial resolution of DIC and made high-resolution strain measurement possible. Both static error analysis and four point-bending experiments were performed to demonstrate the feasibility and effectiveness of the proposed method, and a full-field strain resolution of 10 με was achieved.