Grid Calibration

In its deployment environment, the In-Sight vision system may capture images that exhibit distortions induced by certain setup conditions, such as lens and perspective distortions. Some lens may produce barrel or pincushion radial distortion patterns which cause lines which appear straight in the real-world to appear as curved lines in the image. Perspective distortion is induced when an In-Sight vision system cannot be mounted perpendicular to the inspection area. In these situations, the features in the image may appear stretched or oblong, depending on their location within the field of view, resulting in inaccurate results.

The Grid Calibration option creates a "map" of the image area by acquiring an image of a grid pattern of either dots or checkerboard squares. This option then relates the found features of the grid (the dots or intersections of squares) to the user-specified grid spacing of the grid pattern. This process creates a highly accurate computation that can then be used to transform distorted features into their correct shape.

Calibrating an In-Sight vision system enables you to more accurately locate objects at the edges of images, and provides greater mounting flexibility, including the ability to mount the In-Sight vision system up to 45° from the inspection surface.

Tip: If your application requires Grid Calibration, you can use the Transform Image Filter Tool to view undistorted results and have other inspection tools reference its Tool Image output.

Select Grid from the Calibration Type drop-down menu.
Press the Calibrate button, which will launch the CalibrateGrid Dialog. For more information, see the In-Sight^® Explorer Help file.