ExtractCalibration

ExtractCalibration creates a 2D transformation, in real-world coordinates, based on the "undistorted" image returned by a TransformImage function, and retrieves calibration data contained in the Image data structure output by the NeighborFilter, PointFilter or ScaleImage functions. For more information, see TransformImage, NeighborFilter, PointFilter, or ScaleImage. The ExtractCalibration also supports extracting calibration data contained in the ExtractColorLib data structure output by an ExtractColor function. For more information, see ExtractColor.

Note: For the ExtractColor, NeighborFilter, PointFilter and ScaleImage functions to work correctly with ExtractCalibration, those functions' Image parameter must be set as a reference to a function that returns a Calib data structure.

When a TransformImage function is added, ExtractCalibration is automatically inserted to associate a 2D transformation to the real-world coordinates defined by the image generated by a TransformImage function. Using the Image data structure generated by the TransformImage function as its sole input, ExtractCalibration returns a Calib data structure, which can be used as a reference when a TransBlobsToWorld, TransEdgesToWorld, TransFixtureToWorld, TransPatternsToWorld, and/or TransPixelToWorld function was being used on the undistorted image generated by a TransformImage function. For more information, see Structures, TransBlobsToWorld, TransEdgesToWorld, TransFixtureToWorld, TransPatternsToWorld, or TransPixelToWorld. ExtractCalibration and TransformImage can be associated together using the CalibrateImage function. For more information, see CalibrateImage.

Separately, ExtractCalibration can be inserted into the spreadsheet and its Image parameter set as a reference to the Image data structure output by the NeighborFilter, PointFilter or ScaleImage functions, or the ExtractColorLib data structure output by an ExtractColor function. ExtractCalibration then retrieves the calibration data being fed into these functions.

Note: The output of any vision tool that reports in real-world coordinates cannot be used as a fixture or region input to another vision tool.

ExtractCalibration Inputs

Syntax: ExtractCalibration(Image)

Parameter	Description
Image	This argument must reference a spreadsheet cell that contains a valid Image data structure created by a NeighborFilter, PointFilter, ScaleImage or TransformImage function, or a valid ExtractColorLib data structure created by an ExtractColor function. When automatically inserted in conjunction with a TransformImage function, by default, the cell referenced is the cell containing the Image data structure returned by TransformImage; otherwise the cell referenced is A0, containing the Image data structure returned by AcquireImage. For more information, see AcquireImage.

Parameter

Description

Image

This argument must reference a spreadsheet cell that contains a valid Image data structure created by a NeighborFilter, PointFilter, ScaleImage or TransformImage function, or a valid ExtractColorLib data structure created by an ExtractColor function. When automatically inserted in conjunction with a TransformImage function, by default, the cell referenced is the cell containing the Image data structure returned by TransformImage; otherwise the cell referenced is A0, containing the Image data structure returned by AcquireImage. For more information, see AcquireImage.

ExtractCalibration Outputs

Returns

A Calib data structure containing the coefficients that define the transformation between the two coordinate systems.