Chapter 25: Calibrating your camera setup

This chapter describes how to use MIL's Calibration module.

• Camera calibration - overview
• • Types of distortions
  • Calibration mechanism
• Steps to performing a calibration
• Basic concepts for the MIL Camera Calibration module
• Coordinate systems
• • Absolute world coordinate system
  • Relative world coordinate system
  • Tool coordinate system
  • Camera coordinate system
  • Robot-base coordinate system
  • Pixel coordinate system
• Uniform calibration and other calibration modes
• • Uniform mode
  • Piecewise linear interpolation mode
  • Perspective transformation mode
  • Tsai-based mode
  • Robotics mode
• Calibration propagation
• • Processing calibrated images
  • Saving and reloading a calibrated image
  • • Saving the calibration with the image file
    • Saving the associated calibration context in a separate file
• Working with real-world units
• • Getting results in world units
  • Input settings in world units
  • Angle convention in MIL
• Calibrating using calibration points from a grid or a list
• • Real-world grid
  • • Image of the grid
    • Specifying the top-left corner of your grid
  • List of coordinates
• Inquiring about your calibration
• • Calibration status and errors
  • Calibration accuracy
  • Position and orientation of coordinate systems
  • Pinhole camera
• Physically correcting an image
• • Generating lookup tables to correct images
  • Scale and position of the corrected image
  • Transformation cache
• Moving coordinate systems to reflect camera setup changes
• • Types of transformation
  • • Translation
    • Rotation
  • Transforming coordinate systems
  • Moving the camera after calibrating with a 3D-based calibration context
  • Special considerations concerning the tool and camera coordinate systems
• Calibrating a camera setup that analyzes large objects
• • Single camera fixed on a movable tool (manipulator): tool coordinate system example
  • Single camera and movable object: relative coordinate system example
  • Several fixed cameras and fixed object: grid offset example
• Propagating calibration information after performing a geometric operation
• How coordinates and non-positional results are transformed
• • Transforming from the pixel to a specified world coordinate system
  • Transforming from the world to the pixel coordinate system
  • Transforming from one world coordinate system to another
  • Generating unit vectors from the pixel coordinate system (or vice-versa)
  • Transforming coordinates from a depth map to a world coordinate system (or vice-versa)
  • Using piecewise linear calibrations
  • Transforming Results