User Manual

Holding the grid upside down is a common mistake made during calibration. Spotting this in this case is easy
because the green lines from the grid corners into the green areas will cross each other as shown in Fig. 6.6.4.
Fig. 6.6.4: Wrongly holding the grid upside down leads to crossed green lines.
Note: Calibration might appear cumbersome as it involves holding the grid in certain predefined poses. How-
ever, only this can ensure an unbiased, high-quality calibration result.
Monocalibration
Full calibration consists of calibrating each camera individually and then performing a stereo calibration to deter-
mine the relationship between them. In most cases, the intrinsic calibration of each camera does not get corrupted.
For this reason, Skip Monocalibration in the Calibrate tab should be clicked to skip monocalibration during the
first recalibration. Continue with the guidelines given in Stereo calibration. If stereo calibration yields an unsatis-
factory calibration error, then calibration should be repeated without skipping monocalibration.
The monocalibration process involves five poses for each camera as shown in Fig. 6.6.5.
Fig. 6.6.5: Poses required for monocamera calibration
After the corners or sides of the grid are placed on top of the sensitive areas, the process automatically shows the
next pose required. When the process is finished for the left camera, the same procedure is repeated for the right
one.
Stereo calibration
After monocalibration is completed or has been skipped, the stereo calibration process is started. During stereo
calibration, both cameras are calibrated to each other to find their relative rotation and translation.
6.6. Camera calibration 52