3D Reconstruction Based on Single Defocused Microscopic Image

2012 ◽  
Author(s):  
Z. G. Xing ◽  
C. M. Zhao ◽  
J. Wei ◽  
Z. Wei
Keyword(s):  
3D Reconstruction ◽  
High Speed ◽  
Measurement Accuracy ◽  
Low Cost ◽  
Three Dimensional ◽  
Reconstruction Method ◽  
Microscopic Image ◽  
Depth Of Focus ◽  
Fuzzy Degree

Microscope has being limited by the depth of focus, while the focused image is clear, the defocused images are fuzzy and fuzzy degree of the object images vary with different defocused distances. This paper presented a 3D reconstruction method based on a defocused microscopic image. After the defocused microscopic image is divided the microscopic into M × N regions, the fuzzy degree of each region is quantitatively evaluated. A corresponding curve of the relation between fuzzy degree and defocus distance is drawn by the presented algorithm in this paper, and then the three-dimensional characteristics of objects are reconstructed. This method has the merits of little computation, low cost and high speed. And M and N values can be changed according to the needs of the measurement accuracy.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

scholarly journals Structured-Light Based 3D Reconstruction System for Cultural Relic Packaging

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2981 ◽  
Author(s):  
Limei Song ◽  
Xinyao Li ◽  
Yan-gang Yang ◽  
Xinjun Zhu ◽  
Qinghua Guo ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
High Efficiency ◽  
Low Cost ◽  
Structured Light ◽  
Three Dimensional ◽  
Cloud Data ◽  
Dimensional Measurement ◽  
Cost System ◽  
Three Dimensional Measurement ◽  
Cultural Relics

The non-contact three-dimensional measurement and reconstruction techniques have played a significant role in the packaging and transportation of precious cultural relics. This paper develops a structured light based three-dimensional measurement system, with a low-cost for cultural relics packaging. The structured light based system performs rapid measurements and generates 3D point cloud data, which is then denoised, registered and merged to achieve accurate 3D reconstruction for cultural relics. The multi-frequency heterodyne method and the method in this paper are compared. It is shown that the relative accuracy of the proposed low-cost system can reach a level of 1/1000. The high efficiency of the system is demonstrated through experimental results.

Automation of Tilt Series Acquisition in Transmission Electron Microscopy for Applications in Biology and Materials Science

2001 ◽  
Vol 7 (S2) ◽  
pp. 88-89
Author(s):  
Ingo Daberkow ◽  
Bernhard Feja ◽  
Peter Sparlinek ◽  
Hans R. Tietz
Keyword(s):  
3D Reconstruction ◽  
Data Acquisition ◽  
San Francisco ◽  
High Speed ◽  
Materials Science ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Max Planck ◽  
Automatic Data ◽  
Tilt Series

During the last decade, computation of a three-dimensional image from a tilt series (3D reconstruction) has become a well established method, of which a variety of implementations are available. The term “electron tomography” is now generally used for this type of data acquisition and 3D reconstruction. An overview over the techniques involved is given in.With the introduction of micro-processor-controlled TEMs and cooled slow-scan CCD cameras and with the progress in performance of high-speed computers, automation of complex imaging procedures became mainly a task of developing appropriate software, using the control facilities of the microscope. in this way, automated electron tomography was realized in 1990 at the Max- Planck-Institute for Biochemistry in Martinsried, and at about the same time at the University of California in San Francisco (UCSF). New techniques for automatic focusing and alignment, developed somewhat earlier , have been integrated in these automated tomography procedures. in the following we discuss the requirements of automatic data acquisition and the present implementation for several TEMs.

A modified Fresnel-based algorithm for 3D microwave imaging of metal objects

2018 ◽  
Vol 11 (4) ◽  
pp. 313-325
Author(s):  
Farshad Zamiri ◽  
Abdolreza Nabavi
Keyword(s):  
High Speed ◽  
Fourier Transforms ◽  
Low Cost ◽  
Three Dimensional ◽  
Computation Time ◽  
Microwave Imaging ◽  
Reconstruction Algorithms ◽  
Clock Frequency ◽  
Pipeline Architecture ◽  
The Impact

AbstractMicrowave holography technique reconstructs a target image using recorded amplitudes and phases of the signals reflected from the target with Fast Fourier Transform (FFT)-based algorithms. The reconstruction algorithms have two or more steps of two- and three-dimensional Fourier transforms, which have a high computational load. In this paper, by neglecting the impact of target depth on image reconstruction, an efficient Fresnel-based algorithm is proposed, involving only one-step FFT for both single- and multi-frequency microwave imaging. Numerous tests have been performed to show the effectiveness of the proposed algorithm including planar and non-planar targets, using the raw data gathered by means of a scanner operating in X-band. Finally, a low-cost and high-speed hardware architecture based on fixed-point arithmetic is introduced which reconstructs the planar targets. This pipeline architecture was tested on field programmable gate arrays operating at 200 MHz clock frequency, which illustrates more than 30 times improvement in computation time compared with a computer.

3D reconstruction of human head based on consumer RGB-D sensors

2020 ◽  
pp. 2050061
Author(s):  
Zihan Liu ◽  
Guanghong Gong ◽  
Ni Li ◽  
Zihao Yu
Keyword(s):  
3D Reconstruction ◽  
Low Cost ◽  
Three Dimensional ◽  
Human Head ◽  
Point Clouds ◽  
Microsoft Kinect ◽  
Head Model ◽  
Registration Method ◽  
Three Dimensional Modeling ◽  
Texture Generation

Three-dimensional (3D) reconstruction of a human head with high precision has promising applications in scientific research, product design and other fields. However, it still faces resistance from two factors. One is inaccurate registration caused by symmetrical distribution of head feature points, and the other is economic burden due to high-accuracy sensors. Research on 3D reconstruction with portable consumer RGB-D sensors such as the Microsoft Kinect has been highlighted in recent years. Based on our multi-Kinect system, a precise and low-cost three-dimensional modeling method and its system implementation are introduced in this paper. A registration method for multi-source point clouds is provided, which can reduce the fusion differences and reconstruct the head model accurately. In addition, a template-based texture generation algorithm is presented to generate a fine texture. The comparison and analysis of our experiments show that our method can reconstruct a head model in an acceptable time with less memory and better effect.

scholarly journals 3D Reconstruction of Exposed Underground Utilities Using Photogrammetric Methods

2021 ◽  
Author(s):  
Wensong Hu
Keyword(s):  
3D Reconstruction ◽  
Digital Images ◽  
Low Cost ◽  
Three Dimensional ◽  
Lookup Table ◽  
Image Point ◽  
Digital Cameras ◽  
Study Results ◽  
Underground Utilities ◽  
3D Information

This thesis addresses the topic of three-dimensional (3D) reconstruction of exposed underground utilities using photogrammetric methods. Research on this topic is mainly motivated by the need for improved information on the location of underground utilities and, thus, to provide reliable information for the management of buried assets. In this thesis, a system of photogrammetric software programs is developed for 3D reconstruction of underground utilities. Camera calibration programs are used for computing interior elements and lens distortion coefficients of digital cameras and saving them in a lookup table (LUT). The accuracy of calibrated image coordinates satisfies the photogrammetric processing demand. An automatic image point detection method is proposed and achieved in these programs. External orientation programs are used for calculating exterior elements of the digital images. Based on geographic information system (GIS) and global positioning system (GPS) techniques, a new ground control points (GCPs) collection method is proposed and implemented in these programs. A 3D reconstruction program provides corresponding functions to obtain and edit 3D information of underground utilities. Epipolar lines are employed as an assisting tool that helps operators easily find homologous points from different digital images. The study results indicate that photogrammetric methods for reconstructing 3D information of underground utilities are effective and low cost.

A 3D Reconstruction Method Based on Binocular View Geometry

2010 ◽  
Vol 33 ◽  
pp. 299-303
Author(s):  
Zhong Yan Liu ◽  
Guo Quan Wang ◽  
Dong Ping Wang
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Reconstruction Method ◽  
Feature Points ◽  
Imaging Model ◽  
Extrinsic Parameters ◽  
Image Acquisition System ◽  
Rearview Mirror ◽  
3D Information ◽  
Intrinsic And Extrinsic Parameters

A method was proposed to gain three-dimensional (3D) reconstruction based on binocular view geometry. Images used to calibrate cameras and reconstruct car’s rearview mirror by image acquisition system, by calibration image, a camera's intrinsic and extrinsic parameters, projective and fundamental matrixes were drawn by Matlab7.1;the collected rearview mirror images is pretreated to draw refined laser, extracted feature points, find the very appropriate match points by epipolar geometry principle; according to the camera imaging model to calculate the coordinates of space points, display point cloud, fitting space points to reconstruct car’s rearview mirror; experimental results show this method can better restore the car’s rearview mirror of 3D information.

Height Measurement Based on Fringe Projection

2014 ◽  
Vol 487 ◽  
pp. 298-301
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Nor Shakirina Nadzri ◽  
Christopher John Veriven
Keyword(s):  
High Speed ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Phase Shifting ◽  
Fringe Projection ◽  
Surface Measurement ◽  
Height Measurement ◽  
Cost Measurement ◽  
The Cost ◽  
Factor Technique

A three-dimensional surface measurement using fringe projection technique has received attention among the researches for the last few decades.However choosing the best method is the challenge because one needs to consider the cost, measurement speed, system complexity, measurement accuracy and data reliability to ensure the success of the measurement. This paper focused on the successful manipulation of non-collimated light source and three step phase shifting for height measurement of a lead frame.The measurement done based on pixel determination from the saw tooth image. In addition, the scaling factor technique has been employed for the measurement accuracy. The experimental results achieved a high precision of measurement with simple system and high speed capability.

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