ABB FlexLoader Vision Product Manual page 101

from the edge of the camera (not the lens) to the calibration plate, see the image
below.
xx1800001057
Pos.
A
B
C
Perspective Correction
Perspective correction is always used to take into account the different edge heights
of details above the calibration plate. From the camera viewpoint, details that are
in the same location but have different edge heights appear to be in different
locations in the field of view (known as parallax error). FlexLoader Vision therefore
has a built-in perspective correction technology that automatically compensates
for this effect.
The perspective center (the point in the field of view where the camera is looking
vertically down on to the conveyor) must be specified in order for the automated
correction to work. There are three ways of finding the perspective center:
Product manual - FlexLoader Vision
3HAC051771-001 Revision: B
Description
Camera
Camera height
Calibration plate
• Place a mirror on the conveyor underneath the camera. Look for the camera
lens in the image (a dark round spot). Right-click on the image and select
Show cursor position, followed by Position in pixels. Point at the middle of
the camera lens spot and note the x and y coordinates. Enter these
coordinates as Perspective center X and Perspective center Y.
• Attach the calibration device on the robot, move it directly above the picking
area and tilt it so that the tip can be clearly seen in the camera image. Then
move the robot tip up and down in camera coordinate system, while you
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7 Camera
7.1 2D camera settings
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