Dual Extruder Sub Millimeter Calibration

Sub millimeter calibration pattern. Each line is slightly translated by 0.1 mm offset. Find the line that best match the other line, count the offset from the center (the long line), multiply it by 0.1 and update the software.
The squares give you an indication of offsets that are greater than 1 mm. The box with the cross gives you another very good offset indication.