Camera calibration is a critical task for obtaining accurate real-world measurements in machine vision applications. With it’s 3D calibration operators, HALCON 12 provides an extremely accurate method to calculate the camera parameters as well as the 3D position and orientation of the measurement plane relative to the camera.
MVTec have introduced a new, redesigned calibration target that eases the process significantly. The new plate contains more calibration marks providing better radial lens distortion correction with fewer images. It also features multiple unique finder patterns embedded within the hexagonal mark array. Since only one finder pattern needs to be visible in the image for calibration, you can easily cover the entire field of view with calibration marks. For 2D measurement applications, this means you can calibrate your camera with one single image. For a full 3D calibration it is still necessary to acquire several images from different perspectives, but you need far fewer images in order to achieve the same level of accuracy as the old method.
Having multiple unique finder patterns allows images from multiple cameras observing different portions of the same plate to be mapped into the same world coordinate system. This enables you to perform calibrated image stitching without the need for a custom fixture to hold several targets at precisely known distances
HALCON 12 continues to support the old calibration target, and as with previous versions of HALCON, it is still possible to print your own plates for testing purposes. Printed targets should not be used for high accuracy applications, however. MVTec offers the new calibration target in several different sizes ranging from 20mm x 15mm up to 320mm x 240mm.
For more information on the new calibration targets available with HALCON 12 contact Multipix