Michael Norel - High Accuracy Camera Calibration

High accuracy camera calibration

Michael Norel

Head of R&D at Augmented Pixels

michael@augmentedpixels.com

High accuracy camera calibration

- importance- robustness

Current state

- openCV - matlab- current approach

Problems

- features precise location- errors of corner location - errors of ellipse center - perspective(radial) warp

Systematic noise

- from location errors - from luminance offsets

High accuracy calibration

- introduction to high accuracy - old style calibration without errors - subpixel accuracy - precise marker location

Digital image correlation

frontal image (fronto-parallel)

Digital image correlation

brief intro onto DIC precision(sort of precise optical flow)

Digital image correlation

- circular marker approach- model based- symmetric

Bundle adjustment

- imperfection of calibration pattern - real feature locations

Numeric problems

- importance of parametrization- optimization stuck- different cost functions

Uncertainty

- correct uncertainty estimation- cross correlation- parameters elimination

Just do it

- how to eliminate errors from symmetric correlation?

- different types of parametrization

- new types of fiducial markers

- contribute to openCV, add your name to CV history

list of sources

1. «Advanced geometric camera calibration for machine vision» Minh Vo,Zhaoyang Wang,Long Luu,and Jun Ma

2. «Precision Landmark Location for Machine Vision and Photogrammetry», Jose A.Gutierrez , Brian S.R. Armstrong

3. «Image Correlation for Shape, Motion and Deformation Measurements», Michael A. Sutton, Jean-José Orteu, Hubert W. Schreier

Questions?