An Automatic Calibration Method in the Crop Architecture 3D Scanner

2011 ◽  
Vol 204-210 ◽  
pp. 493-497
Author(s):  
Sheng Yong Xu ◽  
De Hua Li ◽  
Zhu Li ◽  
Qing Wei
Keyword(s):  
Three Dimensional ◽  
Calibration Method ◽  
Reference Points ◽  
Scanning System ◽  
Automatic Calibration ◽  
Automatic Method ◽  
Essential Work ◽  
3D Scanner ◽  
Average Value ◽  
Calibration Parameters

Calibration is an essential work in three-dimensional scanning system. The operation of existing calibration is complex and tedious. In this paper, we design a DLT-based automatic method of calibration, in which the calibration reference points are detected automatically. Then we can figure out a series of calibration parameters from these points. The average value of all parameters is just the calibration parameters. The experimental results show that the method we proposed is not only guaranteeing the calibration precision but also simplifying the calibration operation comparing with the traditional manual calibration method.

Improving the Accuracy of Robot-Based Measuring System by Calibrating Laser-Stripe Scanner Model and Hand-to-Scanner Transformation

2010 ◽  
Vol 44-47 ◽  
pp. 707-711
Author(s):  
Ai Guo Li ◽  
Xiang Wu ◽  
De Feng Wu ◽  
Wen Biao Wang
Keyword(s):  
Industrial Robot ◽  
Calibration Method ◽  
Reference Points ◽  
Measuring System ◽  
Calibration Error ◽  
Scanning System ◽  
System A ◽  
Laser Stripe ◽  
Object Inspection ◽  
Scanner Calibration

This paper focuses on the system for object inspection by use of a laser stripe scanner and an industrial robot. In order to ensure the precision of the scanning system, a one-stage calibration method is proposed. This scheme mainly utilizes a circular-marked board as calibration target and calibrated the scanner model and hand-to-scanner transformation simultaneously using the same reference points. Therefore the influences of the scanner calibration error on the hand-to-scanner calibration can be eliminated naturedly. Finally, some experimental results are reported and analyzed.

scholarly journals Automatic calibration method of voxel size for cone-beam 3D-CT scanning system

2014 ◽  
Vol 38 (4) ◽  
pp. 046202 ◽  
Author(s):  
Min Yang ◽  
Xiao-Long Wang ◽  
Yi-Peng Liu ◽  
Fan-Yong Meng ◽  
Xing-Dong Li ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Calibration Method ◽  
Cone Beam ◽  
Scanning System ◽  
Automatic Calibration ◽  
3D Ct ◽  
Voxel Size

scholarly journals AN IMAGE-BASED INEXPENSIVE 3D SCANNER

2003 ◽  
Vol 03 (02) ◽  
pp. 235-263
Author(s):  
ULAŞ YILMAZ ◽  
ADEM YAŞAR MÜLAYİM ◽  
VOLKAN ATALAY
Keyword(s):  
Rotation Axis ◽  
Three Dimensional ◽  
Calibration Method ◽  
Correction Method ◽  
Controlled Environment ◽  
Model Reconstruction ◽  
3D Scanner ◽  
Rigid Object ◽  
Bounding Volume

An image-based model reconstruction system is described in this paper where real images of a rigid object acquired under a simple but controlled environment are used to recover its three dimensional geometry and its surface texture. Based on a multi-image calibration method, an algorithm to extract the rotation axis of a turn-table has been developed. Furthermore, this algorithm can be extended to estimate robustly the initial bounding volume of the object to be modeled. The coarse volume obtained is then carved using a stereo correction method which removes the disadvantages of silhouette-based reconstruction by photoconsistency. The concept of surface particles is adapted in order to extract a texture map for the model. Some existing metrics are used to measure the quality of the reconstructed models.

scholarly journals MORPHOLOGICAL MODELING OF BAR DYNAMICS WITH DELFT3D: THE QUEST FOR OPTIMAL FREE PARAMETER SETTINGS USING AN AUTOMATIC CALIBRATION TECHNIQUE

2011 ◽  
Vol 1 (32) ◽  
pp. 60 ◽  
Author(s):  
Christophe Briere ◽  
Alessio Giardino ◽  
Jebbe Van der Werf
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Sand Transport ◽  
Automatic Calibration ◽  
Physical Processes ◽  
Calibration Technique ◽  
Validation Test ◽  
Morphological Modeling ◽  
Morphodynamic Evolution ◽  
Calibration Parameters

The modeling of bar dynamics is crucial for understanding coastal dynamics and shoreface nourishment evolution. Due to the complexity and variability of the physical processes involved, the formulations developed within the process-based numerical modelling system Delft3D for representing the forcing of the morphodynamic processes (waves, currents, sand transport) contain a high number of calibration parameters. Therefore, the setting up of any Delft3D computation requires a tedious calibration work, usually carried out manually and therefore by definition subjective. The aim of this work is the setting up of an automated and objective calibration procedure for Delft3D morphodynamic computations. A number of calibration parameters have been identified based on a careful sensitivity analysis. The calibration method named DUD (Does not Use Derivatives) is selected and coupled to a alongshore uniform Delft3D model. The validity of the implementation is shown based on synthetic tests (twin experiments). The validation test is carried out using field data collected at Egmond-aan-Zee (The Netherlands). This paper shows that the tool can be successfully used to calibrate Delft3D. However, further research is especially required to understand whether the computed parameters settings only simulate the best morphodynamic evolution of the bars or also describe properly the underlying physical processes.

scholarly journals Calibrating 3D Scanner in the Coordinate System of Optical Tracker for Image-To-Patient Registration

2021 ◽  
Vol 15 ◽  
Author(s):  
Wenjie Li ◽  
Jingfan Fan ◽  
Shaowen Li ◽  
Zhaorui Tian ◽  
Zhao Zheng ◽  
...  
Keyword(s):  
Coordinate System ◽  
Surgical Navigation ◽  
Three Dimensional ◽  
Operation Time ◽  
Calibration Method ◽  
Phantom Study ◽  
3D Scanner ◽  
Registration Method ◽  
Registration Error ◽  
Patient Registration

Three-dimensional scanners have been widely applied in image-guided surgery (IGS) given its potential to solve the image-to-patient registration problem. How to perform a reliable calibration between a 3D scanner and an external tracker is especially important for these applications. This study proposes a novel method for calibrating the extrinsic parameters of a 3D scanner in the coordinate system of an optical tracker. We bound an optical marker to a 3D scanner and designed a specified 3D benchmark for calibration. We then proposed a two-step calibration method based on the pointset registration technique and nonlinear optimization algorithm to obtain the extrinsic matrix of the 3D scanner. We applied repeat scan registration error (RSRE) as the cost function in the optimization process. Subsequently, we evaluated the performance of the proposed method on a recaptured verification dataset through RSRE and Chamfer distance (CD). In comparison with the calibration method based on 2D checkerboard, the proposed method achieved a lower RSRE (1.73 mm vs. 2.10, 1.94, and 1.83 mm) and CD (2.83 mm vs. 3.98, 3.46, and 3.17 mm). We also constructed a surgical navigation system to further explore the application of the tracked 3D scanner in image-to-patient registration. We conducted a phantom study to verify the accuracy of the proposed method and analyze the relationship between the calibration accuracy and the target registration error (TRE). The proposed scanner-based image-to-patient registration method was also compared with the fiducial-based method, and TRE and operation time (OT) were used to evaluate the registration results. The proposed registration method achieved an improved registration efficiency (50.72 ± 6.04 vs. 212.97 ± 15.91 s in the head phantom study). Although the TRE of the proposed registration method met the clinical requirements, its accuracy was lower than that of the fiducial-based registration method (1.79 ± 0.17 mm vs. 0.92 ± 0.16 mm in the head phantom study). We summarized and analyzed the limitations of the scanner-based image-to-patient registration method and discussed its possible development.

scholarly journals A Flexile and High Precision Calibration Method for Binocular Structured Light Scanning System

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jianying Yuan ◽  
Qiong Wang ◽  
Bailin Li
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
Calibration Method ◽  
Bundle Adjustment ◽  
Reference Object ◽  
Scanning System ◽  
Structured Light Scanning ◽  
Extrinsic Parameters ◽  
Precision Level ◽  
The Cost

3D (three-dimensional) structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional) or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system.

scholarly journals 0689 Use Of An Automated Scanning System To Select A Patient Interface

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A263-A263
Author(s):  
W Hardy ◽  
J Jasko ◽  
R Bogan
Keyword(s):  
Selection Process ◽  
Three Dimensional ◽  
Controlled Study ◽  
Adherence Rate ◽  
Scanning System ◽  
3D Scanner ◽  
Open Label ◽  
Sleep Centers ◽  
Automated Scanning ◽  
The Impact

Abstract Introduction There is no universal process for selecting mask style, size, and fit, and there is considerable variance in clinician and patient mask preference and patient anatomy. Poor mask fit may negatively affect adherence. A three-dimensional (3D) facial scanner and proprietary analytical software were developed to bring efficiencies to mask selection. This study explored the impact of that system on initial mask success compared to standard practice. Methods This was an open-label, randomized-controlled study. Participants provided written informed consent. 3D Scanner Arm (3DA): Participants answered questions about sleeping habits then had 3D facial images taken. Proprietary software recommended a hierarchy of up to four Philips Respironics masks and sizes. Traditional Fitting Arm (TFA): A designated clinician selected and fit masks using their standard methods. Mask selection was assessed by applying therapy and soliciting patient and clinician feedback. Mask refits and adherence were tracked through 90 days. Five sleep centers recruited 115 participants into the 3DA (61 males, 51.1±13.4 years, BMI 35.2±7.0, diagnostic AHI 26.2±21.9) and 123 into the TFA (79 males, 51.1±11.9 years, BMI 35±7.9, diagnostic AHI 26.9±22.6). Results A significantly higher percentage of 3DA patients required only one mask fitting (with no refits) compared to TFA during the initial setup (89.6% vs. 54.5%, p<0.001) and through 90 days (62.6% vs 37.4%, p<0.001). 3DA subjectively rated confidence in and satisfaction with the scanner-selected mask significantly higher than TFA. Mask leak was lower in the 3DA compared to TFA (29.4±10.6 vs 32.3±11.4 L/M, p= 0.043). The CMS adherence rate tended to favor 3DA vs. TFA (66.7% vs. 55.3, p=0.083). There were no significant differences in AHI or other adherence metrics. Conclusion The 3D scanner system was successful in mask selection with lower mask leak and greater patient satisfaction and confidence. This tool may bring about operational efficiencies to the mask selection process. Support This study was sponsored by Philips Respironics

scholarly journals Three-Dimensional Evaluation of the Depressor Anguli Oris and Depressor Labii Inferioris for Botulinum Toxin Injections

2020 ◽  
Author(s):  
You-Jin Choi ◽  
Young-Jun We ◽  
Hyung-Jin Lee ◽  
Kang-Woo Lee ◽  
Young-Chun Gil ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Soft Tissue ◽  
Botulinum Toxin Type A ◽  
Three Dimensional ◽  
Botulinum Toxin Type ◽  
Reference Points ◽  
Scanning System ◽  
Soft Tissue Thickness ◽  
Depressor Anguli Oris ◽  
3D Scans

Abstract Background Botulinum toxin type A (BoNT-A) injection administered at an inappropriate site or depth can produce an unwanted change in facial animation because the depressor anguli oris (DAO) and depressor labii inferioris (DLI) muscles are partially overlapped. Therefore, simple BoNT-A injection guidelines, based on 3-dimensional (3D) facial anatomic references and landmarks, would be very useful. Objectives The aim of this study was to establish novel BoNT-A injection guidelines that include the soft tissue thickness at the lower perioral region. Data were acquired with a 3D scanning system combined with dissections in order to obtain accurate injection sites and depths for the DAO and DLI. Methods 3D scans of the facial skin, superficial fat, and facial muscle surface were performed in 45 embalmed cadavers. The thicknesses of the skin and subcutaneous layer were calculated automatically from superimposed images at each of 5 reference points (P) in the perioral region. Results In every case (100%), P3 and P5 were located in the DLI and DAO areas, respectively (45/45). Therefore, we defined P3 as the “DLI point” and P5 as the “DAO point.” The soft tissue thicknesses at the DLI and DAO points were 6.4 [1.7] mm and 6.7 [1.8] mm, respectively. Conclusions The P3 and P5 described in this study are effective guidelines that only target the DLI and DAO. Clinicians, specifically, can easily use facial landmarks, such as the cheilion and pupil, to assign the DLI and DAO points without any measurement or palpation of the modiolus.

scholarly journals A 3D Machine Vision-Enabled Intelligent Robot Architecture

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yanjun Zhang ◽  
Jianxin zhao ◽  
Heyong Han
Keyword(s):  
Camera Calibration ◽  
Binocular Vision ◽  
Three Dimensional ◽  
Calibration Method ◽  
Transformation Model ◽  
Automatic Calibration ◽  
Robot Architecture ◽  
Positioning Method ◽  
Machine Interface ◽  
Vision Module

In this paper, the principle of camera imaging is studied, and the transformation model of camera calibration is analyzed. Based on Zhang Zhengyou’s camera calibration method, an automatic calibration method for monocular and binocular cameras is developed on a multichannel vision platform. The automatic calibration of camera parameters using human-machine interface of the host computer is realized. Based on the principle of binocular vision, a feasible three-dimensional positioning method for binocular target points is proposed and evaluated to provide binocular three-dimensional positioning of target in simple environment. Based on the designed multichannel vision platform, image acquisition, preprocessing, image display, monocular and binocular automatic calibration, and binocular three-dimensional positioning experiments are conducted. Moreover, the positioning error is analyzed, and the effectiveness of the binocular vision module is verified to justify the robustness of our approach.

scholarly journals Determination of vertical dimension of occlusion by using the phonetic vowel "O" and "E"

2015 ◽  
Vol 72 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Marko Igic ◽  
Nebojsa Krunic ◽  
Ljiljana Aleksov ◽  
Milena Kostic ◽  
Aleksandra Igic ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Complete Denture ◽  
Reference Points ◽  
Vertical Dimension ◽  
Entire Sample ◽  
Average Value ◽  
Significant Difference ◽  
The Relationship

Background/Aim. The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals ?O? and ?E? with the control of values o btained by applying cognitive functions. Methods. This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words ?OLO? and ?ELE?. Checking the correctness of the particular value for the word ?OLO? was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values i n determining the vertical dimension of occlusion and the ?OLO? and ?ELE? in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. Results. The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word ?OLO? for the entire sample was 5.51 mm and for the word ?ELE? for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, ?ELE? and ?OLO?. There was a statistically significant difference between the values f or the vertical dimension at rest, ?OLO? and ?ELE? for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, ?OLO? and ?ELE?, for both groups of subjects. Conclusion. Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word ?OLO? or 7.5 mm in pronunciation of the word ?ELE?.

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