# 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 ScaleImage function.

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

## About ExtractCalibration

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. ExtractCalibration and TransformImage can be associated together using the CalibrateImage function.

Separately, ExtractCalibration can be inserted into the spreadsheet and its Image parameter set as a reference to the Image data structure output by the ScaleImage 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

Parameter | Description
Image | This argument must reference a spreadsheet cell that contains a valid Image data structure created by a ScaleImage or TransformImage 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 $A$0, containing the Image data structure returned by AcquireImage.

## ExtractCalibration Outputs

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