A New Extrinsic Calibration Method of Three-Dimensional Imaging Lidar and Camera

Three-dimensional imaging lidar can offer the range information and CCD camera can offer the color information of the target. These two information can strongly supplement each other, the fusion of them is becoming a research hot point. The major problem of fusing lidar data and camera data is the coordinate calibration between them. In consideration of the traits of lidar and camera, a new planar object calibration method was proposed, which solves extrinsic matrix using the normal of planar objects. The rotation matrix and transfer vector are solved separately, which can simplify the calibration process and highly improve the calibration precision. The improved extrinsic calibration method was applied on texture mapping and reverse mapping, which show that our algorithm can gives good results.

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Simple Calibration Method for Three-Dimensional Imaging System with Structured Light

Laser & Optoelectronics Progress ◽

10.3788/lop56.141102 ◽

2019 ◽

Vol 56 (14) ◽

pp. 141102

Author(s):

张翰 Han Zhang ◽

包国琦 Guoqi Bao ◽

刘凯 Kai Liu

Keyword(s):

Imaging System ◽

Structured Light ◽

Three Dimensional ◽

Calibration Method ◽

Three Dimensional Imaging

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Three Dimensional Shape Measurement of Micro Droplet Utilizing Micro LIF Technique

ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer, Parts A and B ◽

10.1115/mnht2008-52141 ◽

2008 ◽

Author(s):

Yasuhiko Sugii

Keyword(s):

Measurement Accuracy ◽

Three Dimensional ◽

Ccd Camera ◽

Optical Filters ◽

Calibration Method ◽

Two Phase ◽

Depth Direction ◽

High Measurement ◽

Dimensional Shape ◽

Three Dimensional Shape

This paper describes a novel measurement technique for three dimensional shape of micro droplet utilizing micro LIF (Laser Induced Fluorescence) technique. A measurement system consisted of microscope equipped with 10x lens, high sensitive CCD camera, CW Nd:YAG laser, optical filters and so on. Calibration curve between thickness of micro droplet and emission of fluorescence dye solution was obtained by the use of the PDMS (polydimethylsiloxane) microchip, whose depth varied from 8 to 120 μm fabricated using photo lithography technique. The microchip based calibration method provides high measurement accuracy and eliminate photobreaching effect. Measurement accuracy of the present method in depth direction was about 2 μm assessed using laser displace meter and the spatial resolution in the x-y plane became 6.7 μm. The technique is useful to investigate a two phase flow in micro scale.

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A Hybrid Vehicle Extraction Approach from Low-Quality LiDAR Data Based on Robust One-Class Support Vector Machine

International Journal of Pattern Recognition and Artificial Intelligence ◽

10.1142/s0218001417550047 ◽

2017 ◽

Vol 31 (02) ◽

pp. 1755004 ◽

Cited By ~ 1

Author(s):

Yong Wang ◽

Jianyong Liu ◽

Chengqun Fu ◽

Jie Guo ◽

Qin Yu ◽

...

Keyword(s):

Support Vector Machine ◽

High Performance ◽

Hybrid Approach ◽

Three Dimensional ◽

Support Vector ◽

Lidar Data ◽

Color Information ◽

Minimum Covariance Determinant ◽

Multivariate Dispersion ◽

Benchmark Datasets

Vehicle extraction becomes possible as the high-performance airborne light detection and ranging (LiDAR) systems can offer very dense and accurate point cloud, which means the sophisticated objects can be recorded in detail, combined with color information from airborne image, hyperspectral and intensity. However, few studies have investigated in extracting vehicles from LiDAR data only, especially when its quality is low, which is the main difficulty for most LiDAR applications. In this paper, a hybrid approach has been proposed to extract vehicles from low-quality LiDAR data. In order to extract vehicle from low-resolution LiDAR data, a robust one-class support vector machine-minimum covariance determinant (OCSVM-MCD) is proposed based on a multivariate dispersion estimator and weighted strategy. Firstly, the three-dimensional (3D) point dataset is classified into nonterrain and terrain points with progressive morphological filter with a slight improvement. Secondly, nonterrain points are segmented by clustering technique and missing blobs are searched from terrain points. Then, the vehicles are extracted from clustering and searching results by OCSVM-MCD, and a hybrid principle is put forward to improve the extraction result at last. The proposed method has been evaluated with two benchmark datasets from ISPRS, and proved that by the method, most vehicles can be extracted from low-quality LiDAR data with an encouraging result.

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Extrinsic Calibration of 2D Laser Rangefinders Based on a Mobile Sphere

Remote Sensing ◽

10.3390/rs10081176 ◽

2018 ◽

Vol 10 (8) ◽

pp. 1176 ◽

Cited By ~ 4

Author(s):

Shoubin Chen ◽

Jingbin Liu ◽

Teng Wu ◽

Wenchao Huang ◽

Keke Liu ◽

...

Keyword(s):

Autonomous Vehicles ◽

Three Dimensional ◽

Calibration Method ◽

High Accuracy ◽

Sensor Data ◽

Extrinsic Calibration ◽

Practical Applications ◽

Calibration Methods ◽

Simultaneous Location And Mapping ◽

Automatic Matching

In the fields of autonomous vehicles, virtual reality and three-dimensional (3D) reconstruction, 2D laser rangefinders have been widely employed for different purposes, such as localization, mapping, and simultaneous location and mapping. However, the extrinsic calibration of multiple 2D laser rangefinders is a fundamental prerequisite for guaranteeing their performance. In contrast to existing calibration methods that rely on manual procedures or suffer from low accuracy, an automatic and high-accuracy solution is proposed in this paper for the extrinsic calibration of 2D laser rangefinders. In the proposed method, a mobile sphere is used as a calibration target, thereby allowing the automatic extrapolation of a spherical center and the automatic matching of corresponding points. Based on the error analysis, a matching machine of corresponding points with a low error is established with the restriction constraint of the scan circle radius, thereby achieving the goal of high-accuracy calibration. Experiments using the Hokuyo UTM-30LX sensor show that the method can increase the extrinsic orientation accuracy to a sensor intrinsic accuracy of 10 mm without requiring manual measurements or manual correspondence among sensor data. Therefore, the calibration method in this paper is automatic, highly accurate, and highly effective, and it meets the requirements of practical applications.

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X-ray microtomography as a fast three-dimensional imaging technology using a CCD camera coupled with a CdWO4 single-crystal scintillator

10.1117/12.279361 ◽

1997 ◽

Cited By ~ 10

Author(s):

Heung-Rae Lee ◽

Barry P. Lai ◽

Wenbing Yun ◽

Derrick C. Mancini ◽

Zhonghou Cai

Keyword(s):

Single Crystal ◽

Three Dimensional ◽

Ccd Camera ◽

Three Dimensional Imaging ◽

Imaging Technology ◽

X Ray ◽

Title X ◽

Crystal Scintillator

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High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100168827 ◽

1994 ◽

Vol 52 ◽

pp. 218-219

Author(s):

Robert W. Mackin

Keyword(s):

Image Analysis ◽

High Speed ◽

Three Dimensional ◽

Image Data ◽

Ccd Camera ◽

Objective Lens ◽

Array Processor ◽

Vaginal Smears ◽

Low Contrast ◽

Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

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