Rejection of mismatched correspondences along the affine epipolar line

2000 ◽  
Vol 18 (6-7) ◽  
pp. 445-462 ◽  
Author(s):  
Chin-Seng Chua ◽  
Yeong Khing Ho ◽  
Y. Liang
Keyword(s):  
Epipolar Line

3-D Measurement and Reconstruction of Workpieces in Robotic Stereovision System

2015 ◽  
Vol 743 ◽  
pp. 783-786
Author(s):  
He Xi Li ◽  
J.J. Zhang
Keyword(s):  
Measurement Accuracy ◽  
Structural Parameters ◽  
Constraint Equation ◽  
Epipolar Line ◽  
Workpiece Surface ◽  
Reference Base ◽  
3 Dimensional ◽  
Intrinsic Parameters ◽  
Laser Stripe ◽  
Left And Right

An epipolar line constraint equation for robotic binocolar stereovision (BSV) is first established for the measurement and reconstruction of workpiece surface, in which the intrinsic parameters of two cameras and their extrinsic structural parameters with respect to a robotic reference base are included. To determine a sole matching point between left and right images, a laser emmiter is added to BSV to form a stripe on workpiece surface, experimental results show that the measurement accuracy of 3-dimensional (3-D) workpiece surface can be improved by combining epipolar line constraint with laser stripe projection, and the 3-D workpiece surface can be reconstructed with less errors.

Stereo Matching Algorithm Based on Detecting Feature Points

2012 ◽  
Vol 433-440 ◽  
pp. 6190-6194
Author(s):  
Shuo Bo Xu ◽  
Di Shi Xu ◽  
Hua Fang
Keyword(s):  
Stereo Matching ◽  
Characteristic Point ◽  
Feature Points ◽  
Epipolar Line ◽  
Matching Problem ◽  
Matching Algorithm ◽  
Characteristic Points ◽  
Left And Right ◽  
Straight Lines ◽  
Verification Strategy

A new method for solving the stereo matching problem in the presence of large occlusion is presented. This method for stereo matching and occlusion detection is based on searching disparity point. In this paper, we suppose that a pair of epipolar-line images is a projection of a group of piece-wise straight lines on the left and right images respective. Therefore the disparity curve corresponding to a pair of epipolar-line images may be approximated by a group of piece-wise straight lines. Then the key of solving disparity curve is how to get the “characteristic points” on the group of piece-wise straight lines. Based on this view, we fetched out the conception “disparity point”, and three kinds of special disparity points are correctly corresponding to the “characteristic point”. By analyzing intensity property of a disparity point and its neighbor points, an approach which combines stepwise hypothesis-verification strategy with three constraint conditions is devised to extract the candidate disparity points from the epipolar images.

scholarly journals The Accuracy of Virtual Fractional Flow Reserve From Invasive Angiography: Importance of the Method of Reconstructing Three-dimensional Coronary Artery Anatomy

2021 ◽  
Author(s):  
Roshni Solanki ◽  
Rebecca Gosling ◽  
Vignesh Rammohan ◽  
Giulia Pederzani ◽  
Pankaj Garg ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Three Dimensional ◽  
Epipolar Line ◽  
Fractional Flow ◽  
Coronary Anatomy ◽  
Flow Reserve ◽  
3D Printed ◽  
Surface Similarity ◽  
Line Projection

Abstract Background Three dimensional (3D) coronary anatomy, reconstructed from coronary angiography (CA), is now being used as the basis to compute ‘virtual’ fractional flow reserve (vFFR), and thereby guide treatment decisions in patients with coronary artery disease (CAD). Reconstruction accuracy is therefore important. Yet these methods remain poorly validated. Furthermore, the magnitude of vFFR error arising from reconstruction is unkown. We aimed to validate a new method for 3D CA reconstruction and determine the effect this had upon the accuracy of vFFR.Methods Clinically realistic coronary phantom models were created (seven standard stenoses in aluminium and 15 patient-based 3D-printed) and imaged with CA, three times, according to clinical protocols, yielding 66 datasets. Each was reconstructed using epipolar line projection and intersection. All reconstructions were compared against the phantom models in terms of minimal lumen diameter, centreline and surface similarity. 3D-printed reconstructions (n=45) and the reference files from which they were printed underwent vFFR computation, and the results were compared. Results The average error in reconstructing minimum lumen diameter (MLD) was 0.05 (±0.03 mm) which was <1% (95%CI 0.13-1.61%) compared with caliper measurement. Overall surface similarity was excellent (Hausdorff distance 0.65 mm). Errors in 3D CA reconstruction accounted for an error in vFFR of ±0.06 (95% limits of agreement).Conclusions Errors arising from the epipolar line projection method used to reconstruct 3D coronary anatomy from CA are small but result in clinically relevant errors in vFFR simulation, amounting to approximately 40% of the total error associated with vFFR.

scholarly journals 3D Spherical Panoramic Epipolar Line Based on Essential Matrix

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 192165-192176
Author(s):  
Shuai Liu ◽  
Jun Chen ◽  
Min Sun ◽  
Lingli Zhao ◽  
Xiang Wei ◽  
...  
Keyword(s):  
Epipolar Line ◽  
Essential Matrix

UAV Low Altitude Photogrammetry for Power Line Inspection

2016 ◽  
Author(s):  
Yong Zhang ◽  
Xiuxiao Yuan ◽  
Yi Fang ◽  
Shiyu Chen
Keyword(s):  
Transmission Lines ◽  
Three Dimensional ◽  
Digital Camera ◽  
Point Clouds ◽  
Power Line ◽  
Epipolar Line ◽  
3D Point Clouds ◽  
Low Altitude ◽  
Power Line Corridor ◽  
Safety Inspections

When the distance between an obstacle and a power line is less than the discharge distance, a discharge arc can be generated, resulting in interruption of power supplies. Therefore, regular safety inspections are necessary to ensure safe operations of power grids. Tall vegetation and buildings are the key factors threatening the safe operation of extra high voltage transmission lines within a power line corridor. Manual or LiDAR based-inspections are time consuming and expensive. To make safety inspections more efficient and flexible, a low-altitude unmanned aerial vehicle remote-sensing platform equipped with optical digital camera was used to inspect power line corridors. We propose a semi-patch matching algorithm based on epipolar constraints using both correlation coefficient and the shape of its curve to extract three dimensional (3D) point clouds for a power line corridor. Virtual photography was used to transform the power line direction from approximately parallel to the epipolar line to approximately perpendicular to epipolar line to improve power line measurement accuracy. The distance between the power lines and the 3D point cloud is taken as a criterion for locating obstacles within the power line corridor automatically. Experimental results show that our proposed method is a reliable, cost effective and applicable way for practical power line inspection, and can locate obstacles within the power line corridor with measurement accuracies better than &plusmn;0.5 m.

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