Transforming Pixels to Millimeters: Geometric Camera Calibration

About This Seminar

The affordability and ubiquity of cameras have led to their increasing use in many disciplines. In plant phenomics, it is common to see experimental data based on image-derived measurements. This seminar will explain geometric camera calibration, whereby pixel measurements are mapped to physical measurements and the conditions under which participants can calibrate their own cameras. The value of using calibrated cameras in plant science experiments is the possibility of replacing scanners with cameras, using a variety of individual cameras in experiments, and ensuring integrity and consistency of image-derived measurements.

Participants will be able to (learning objectives):

  • Understand basic concepts of camera structure and corresponding geometric concepts, including image plane, principal axis, etc.
  • Understand the typical process of camera calibration using a chessboard pattern.
  • Understand the conditions under which single-camera calibration allows for the computation of measurements.
  • Explore code examples available via the OpenCV library.


Amy Tabb, Ph.D.

Amy Tabb is a research engineer (a PI role) in the U.S. Department of Agriculture’s Agricultural Research Service, working in the Appalachian Fruit Research Station in Kearneysville, West Virginia. Amy’s Ph.D. is in Electrical and Computer Engineering, where she specialized in computer vision. Currently, she also does research in robotics.

View this seminar