Standalone camera calibration, Calibration with a grid of dots – Adept AdeptSight User Guide User Manual

Page 207

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Standalone Camera Calibration

You should calibrate the camera before you create any vision tools. The basic camera cal-
ibration is a "spatial" calibration that corrects for perspective distortion, lens distortion, and
defines the relationship between the camera pixels and real-world dimensions.

You can perform this calibration with just a camera and a calibration grid or fixed-pixel cal-
ibration.

NOTE: The offset of the camera from the robot or other equipment is not part of this cal-
ibration. That information is obtained during the robot-to-camera calibration. Standalone
calibration should be performed first. See Calibrations on page 51.

Calibration with a Grid of Dots

The camera calibration usually uses a grid of dots target. A sample dot target file is provided
with the AdeptSight installation. See Creating a Dot Target on page 213.

NOTE: The sample target is intended for teaching purposes only; it is not a genuine, accu-
rate vision target.

Because any error introduced into the vision system at this calibration will be carried into all
following calibrations, the target should be as accurate as possible.

Adept recommends using a commercial-grade target, available from suppliers such as:

l

Edmund Optics (edmundoptics.com, Fixed Frequency Grid Distortion Targets)

or

l

Applied Image Inc (aig-imaging.com, Accu-Place

TM

Dot Pattern)

Before Calibrating

Correct lighting on the target is important to obtain accurate calibration.

Before starting this calibration, make sure that the entire area covered by the camera field of
view is within the robot work range, if required by your application.

If you have more than one camera installed, select the camera you want to calibrate:

1. Click Device, to highlight that field.

2. Click the drop-down arrow, to display the available cameras.

3. Highlight the camera you want to calibrate.

4. Click OK.

The Vision Display Units field controls the image display from this source. The default is Mil-
limeter. For most applications, this is the setting you will want.

Standalone Camera Calibration

AdeptSight User's Guide, Version 3.2.x, Updated: 8/23/2012

Page 207

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