scholarly journals Real-time correction by optical tracking with integrated geometric distortion correction for reducing motion artifacts in functional MRI

2012 ◽  
Vol 69 (3) ◽  
pp. 734-748 ◽  
Author(s):  
David Rotenberg ◽  
Mark Chiew ◽  
Shawn Ranieri ◽  
Fred Tam ◽  
Rajiv Chopra ◽  
...  
Keyword(s):  
Real Time ◽  
Functional Mri ◽  
Motion Artifacts ◽  
Distortion Correction ◽  
Optical Tracking ◽  
Geometric Distortion ◽  
Time Correction

Real-time correction of geometric distortion artefacts in large-volume optical coherence tomography

2013 ◽  
Vol 24 (5) ◽  
pp. 057001 ◽  
Author(s):  
Sam Van der Jeught ◽  
Jan A N Buytaert ◽  
Adrian Bradu ◽  
Adrian Gh Podoleanu ◽  
Joris J J Dirckx
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Large Volume ◽  
Geometric Distortion ◽  
Optical Coherence ◽  
Time Correction

scholarly journals Real-time geometric distortion correction for interventional imaging with echo-planar imaging (EPI)

2009 ◽  
Vol 61 (4) ◽  
pp. 994-1000 ◽  
Author(s):  
Iulius Dragonu ◽  
Baudouin Denis de Senneville ◽  
Bruno Quesson ◽  
Chrit Moonen ◽  
Mario Ries
Keyword(s):  
Real Time ◽  
Echo Planar Imaging ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Planar Imaging ◽  
Interventional Imaging ◽  
Echo Planar

High speed interferometric device for real-time correction of aero-optic effects

1995 ◽  
Author(s):  
Rod Clark ◽  
John Karpinsky ◽  
Gregg Borek ◽  
Eric Johnson
Keyword(s):  
Real Time ◽  
High Speed ◽  
Time Correction

scholarly journals A Tree Ring Measurement Method Based on Error Correction in Digital Image of Stem Analysis Disk

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 464
Author(s):  
Wenjie Zhang ◽  
Tianzhong Zhao ◽  
Xiaohui Su ◽  
Baoguo Wu ◽  
Zhiqiang Min ◽  
...  
Keyword(s):  
Error Correction ◽  
Tree Ring ◽  
Tree Rings ◽  
Digital Image ◽  
Regression Equation ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Stem Analysis ◽  
Correction Model ◽  
Ring Radius

Stem analysis is an essential aspect in forestry investigation and forest management, as it is a primary method to study the growth law of trees. Stem analysis requires measuring the width and number of tree rings to ensure the accurate measurement, expand applicable tree species, and reduce operation cost. This study explores the use of Open Source Computer Vision Library (Open CV) to measure the ring radius of analytic wood disk digital images, and establish a regression equation of ring radius based on image geometric distortion correction. Here, a digital camera was used to photograph the stem disks’ tree rings to obtain digital images. The images were preprocessed with Open CV to measure the disk’s annual ring radius. The error correction model based on the least-square polynomial fitting method was established for digital image geometric distortion correction. Finally, a regression equation for tree ring radius based on the error correction model was established. Through the above steps, click the intersection point between the radius line and each ring to get the pixel distance from the ring to the pith, then the size of ring radius can be calculated by the regression equation of ring radius. The study’s method was used to measure the digital image of the Chinese fir stem disk and compare it with the actual value. The results showed that the maximum error of this method was 0.15 cm, the average error was 0.04 cm, and the average detection accuracy reached 99.34%, which met the requirements for measuring the tree ring radius by stem disk analysis. This method is simple, accurate, and suitable for coniferous and broad-leaved species, which allows researchers to analyze tree ring radius measurement, and is of great significance for analyzing the tree growth process.

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