TOWARDS THE SELF-CALIBRATION OF A MULTIVIEW RADIOGRAPHIC IMAGING SYSTEM FOR THE 3D RECONSTRUCTION OF THE HUMAN SPINE AND RIB CAGE

1999 ◽  
pp. 189-207
Author(s):  
F. CHERIET ◽  
J. DANSEREAU ◽  
Y. PETIT ◽  
C. -É. AUBIN ◽  
H. LABELLE ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Imaging System ◽  
The Self ◽  
Radiographic Imaging ◽  
Rib Cage ◽  
Human Spine ◽  
Self Calibration

TOWARDS THE SELF-CALIBRATION OF A MULTIVIEW RADIOGRAPHIC IMAGING SYSTEM FOR THE 3D RECONSTRUCTION OF THE HUMAN SPINE AND RIB CAGE

1999 ◽  
Vol 13 (05) ◽  
pp. 761-779 ◽  
Author(s):  
F. CHERIET ◽  
J. DANSEREAU ◽  
Y. PETIT ◽  
C.-É. AUBIN ◽  
H. LABELLE ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Coordinate System ◽  
Imaging System ◽  
The Self ◽  
Reference Plane ◽  
Global Coordinate System ◽  
Optimal Estimate ◽  
Rib Cage ◽  
Human Spine ◽  
Self Calibration

The main objective of this study was to develop a 3D reconstruction technique of the spine and rib cage of idiopathic scoliotic patients using the self-calibration of the imaging system. The proposed approach computes the intrinsic and extrinsic parameters of the radiographic setup with respect to the global coordinate system used at Ste-Justine Hospital. Our approach determines an optimal estimate of the geometrical parameters of the imaging system from a nonlinear minimization of the mean square distance between the observed and analytical projections of a set of matched points identified on a pair of radiographic views. The accuracy of the optimal estimate for the intrinsic parameters was significantly improved when geometric knowledge such as the known length of detectable straight bars is incorporated as a set of equality constraints in the optimization process. Furthermore, in order to retrieve the 3D structure of interest in the global coordinate system, a reference plane including the origin of the global coordinate system is specified. Computer simulations were performed to evaluate the self-calibration procedure and to determine the minimum knowledge required to obtain an accurate 3D reconstruction for clinical applications. An in vitro validation on real images of a dry cadaveric human spine showed that the method is feasible and reaches the expected accuracy.

Camera Calibration for 3D Reconstruction and View Transformation

2011 ◽  
pp. 70-129
Author(s):  
B. J. Lei ◽  
E. A. Hendriks ◽  
Aggelos K. Katsaggelos
Keyword(s):  
3D Reconstruction ◽  
Camera Calibration ◽  
Mathematical Description ◽  
The Self ◽  
Model Reconstruction ◽  
Face Model ◽  
Self Calibration ◽  
Calibration Methods ◽  
View Transformation ◽  
Calibration Techniques

This chapter presents an extensive overview of passive camera calibration techniques. Starting with a detailed introduction and mathematical description of the imaging process of an off-the-shelf camera, it reviews all existing passive calibration approaches with increasing complexity. All algorithms are presented in detail so that they are directly applicable. For completeness, a brief counting about the self-calibration is also provided. In addition, two typical applications are given of passive camera calibration methods for specific problems of face model reconstruction and telepresence and experimentally evaluated. It is expected that this chapter can serve as a standard reference. Researchers in various fields in which passive camera calibration is actively or potentially of interest can use this chapter to identify the appropriate techniques suitable for their applications.

scholarly journals Ultra-High-Resolution 1 m/pixel CaSSIS DTM Using Super-Resolution Restoration and Shape-from-Shading: Demonstration over Oxia Planum on Mars

2021 ◽  
Vol 13 (11) ◽  
pp. 2185
Author(s):  
Yu Tao ◽  
Sylvain Douté ◽  
Jan-Peter Muller ◽  
Susan J. Conway ◽  
Nicolas Thomas ◽  
...  
Keyword(s):  
High Resolution ◽  
3D Reconstruction ◽  
Imaging System ◽  
Processing System ◽  
Digital Terrain Model ◽  
Super Resolution ◽  
Landing Site ◽  
Shape From Shading ◽  
Stereo Pair ◽  
Terrain Model

We introduce a novel ultra-high-resolution Digital Terrain Model (DTM) processing system using a combination of photogrammetric 3D reconstruction, image co-registration, image super-resolution restoration, shape-from-shading DTM refinement, and 3D co-alignment methods. Technical details of the method are described, and results are demonstrated using a 4 m/pixel Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) panchromatic image and an overlapping 6 m/pixel Mars Reconnaissance Orbiter Context Camera (CTX) stereo pair to produce a 1 m/pixel CaSSIS Super-Resolution Restoration (SRR) DTM for different areas over Oxia Planum on Mars—the future ESA ExoMars 2022 Rosalind Franklin rover’s landing site. Quantitative assessments are made using profile measurements and the counting of resolvable craters, in comparison with the publicly available 1 m/pixel High-Resolution Imaging Experiment (HiRISE) DTM. These assessments demonstrate that the final resultant 1 m/pixel CaSSIS DTM from the proposed processing system has achieved comparable and sometimes more detailed 3D reconstruction compared to the overlapping HiRISE DTM.

scholarly journals Automatic Extrinsic Self-Calibration of Mobile Mapping Systems Based on Geometric 3D Features

2019 ◽  
Vol 11 (16) ◽  
pp. 1955 ◽  
Author(s):  
Markus Hillemann ◽  
Martin Weinmann ◽  
Markus S. Mueller ◽  
Boris Jutzi
Keyword(s):  
Spatial Data ◽  
Point Cloud ◽  
Laser Scanner ◽  
The Self ◽  
Geometric Features ◽  
Mobile Mapping ◽  
Extrinsic Calibration ◽  
Self Calibration ◽  
Mobile Mapping Systems ◽  
Mapping Systems

Mobile Mapping is an efficient technology to acquire spatial data of the environment. The spatial data is fundamental for applications in crisis management, civil engineering or autonomous driving. The extrinsic calibration of the Mobile Mapping System is a decisive factor that affects the quality of the spatial data. Many existing extrinsic calibration approaches require the use of artificial targets in a time-consuming calibration procedure. Moreover, they are usually designed for a specific combination of sensors and are, thus, not universally applicable. We introduce a novel extrinsic self-calibration algorithm, which is fully automatic and completely data-driven. The fundamental assumption of the self-calibration is that the calibration parameters are estimated the best when the derived point cloud represents the real physical circumstances the best. The cost function we use to evaluate this is based on geometric features which rely on the 3D structure tensor derived from the local neighborhood of each point. We compare different cost functions based on geometric features and a cost function based on the Rényi quadratic entropy to evaluate the suitability for the self-calibration. Furthermore, we perform tests of the self-calibration on synthetic and two different real datasets. The real datasets differ in terms of the environment, the scale and the utilized sensors. We show that the self-calibration is able to extrinsically calibrate Mobile Mapping Systems with different combinations of mapping and pose estimation sensors such as a 2D laser scanner to a Motion Capture System and a 3D laser scanner to a stereo camera and ORB-SLAM2. For the first dataset, the parameters estimated by our self-calibration lead to a more accurate point cloud than two comparative approaches. For the second dataset, which has been acquired via a vehicle-based mobile mapping, our self-calibration achieves comparable results to a manually refined reference calibration, while it is universally applicable and fully automated.

OP45 HTA Of A Pediatric Biplanar Low-Dose X-Ray Imaging System

2018 ◽  
Vol 34 (S1) ◽  
pp. 17-18
Author(s):  
Martina Andellini ◽  
Francesco Faggiano ◽  
Roxana di Mauro ◽  
Pietro Derrico ◽  
Matteo Ritrovato
Keyword(s):  
3D Reconstruction ◽  
Low Dose ◽  
Imaging System ◽  
Weight Bearing ◽  
Ct Scanning ◽  
Lower Limbs ◽  
Final Decision ◽  
X Ray ◽  
Congenital Deformities ◽  
X Ray Imaging

Introduction:Patients with adolescent idiopathic scoliosis frequently receive X-ray imaging at diagnosis and subsequent follow monitoring. To achieve the ALARA concept of radiation dose, a biplanar low-dose X-ray system (BLDS) has been proposed. The aim of the study is to gather evidence on safety, accuracy and overall effectiveness of a BLDS compared with CT scanning, in a pediatric population, in order to support the final decision on possible acquisition of such innovative diagnostic system.Methods:The new method Decision-oriented HTA (DoHTA) was applied to carefully assess the diagnostic technology. It was developed starting from the EUnetHTA Core Model® integrated with the analytic hierarchy process in order to identify all the relevant assessment aspects of the technology involved, identified from scientific literature, experts’ judgments and specific context analysis of Bambino Gesù Children's Hospital. A weight was associated to each assessment element and the alternatives’ ranking was defined.Results:This innovative system provides orthopedic images in standing or sitting position, being able to examine the spine and lower limbs under normal weight-bearing conditions. This system is recommended for particular clinical indications as scoliosis and other congenital deformities of the spine. It is able to acquire simultaneous posteroanterior and lateral images in a single scan without vertical distortion and with lower radiation exposure than CT scanning. 2D images acquired can be combined to obtain a 3D reconstruction scanning based on a semi-automated statistical model.Conclusions:The major advantages of BLDS are the relatively low dose of radiation and the possibility of obtaining a 3D reconstruction of the bones. Our preliminary results show that data on the clinical effectiveness are limited but the technical advancements of BLDS appear promising in terms of patient management and patient health outcomes associated with its use.

Sign in / Sign up

Export Citation Format

Share Document