ROI Descriptor defines the region of interest to use in the learning process. All circles in the grid that are outside the defined region are not used when estimating the calibration transformation.

	Global Rectangle contains the coordinates of the bounding rectangle.
	Contours are each of the individual shapes that define an ROI. ID refers to whether the contour is the external or internal edge of an ROI. Type is the shape type of the contour. Coordinates indicates the relative position of the contour.

Image is a reference to the template used for calibrating your system. It should be an image of a grid of dots. The contents of this image are not used if the Reference Points array is provided to the VI.

Calibration Learn Setup contains the following values:

	Distortion indicates the type of distortion you can correct when correcting an image: Perspective (0) Image contains perspective calibration information. Nonlinear (1) Image contains nonlinear calibration information. Simple Calibration (2) Image contains simple calibration information (no perspective or nonlinear information). Corrected (3) Image has been corrected and contains calibration unit and scaling factor.
	Corrected Image Scaling defines the aspect scaling to use when correcting an image. Scale to Preserve Area (0) The corrected image is scaled such that the features in the image have the same size as the input image. Scale to Fit (1) The corrected image is scaled to be the same size as the input image.
	Corrected Image Learn ROI specifies the ROI to use when correcting an image. Full Image (0) The whole image is always corrected, regardless of the user-defined or calibration-defined ROIs. Calibration ROI (1) The area defined by the Calibration ROI is corrected. The calibration ROI is computed by the algorithm and corresponds to the area of the calibration template containing dots. ROI (2) The area defined by ROI Descriptor is corrected. ROI AND Calibration ROI (3) The area defined by the intersection of the ROI and Calibration ROI is corrected. ROI OR Calibration ROI (4) The area defined by the union of the ROI and Calibration ROI is corrected.
	Learn Error Map? is a Boolean input value. Set this input to TRUE if you want the software to calculate and store an error map during the learning process. The image error map reflects error bounds on the calibration transformation.
	Learn Correction Table? is a Boolean input value. Set this input to TRUE if you want the correction table to be determined and stored. The correction table accelerates the process of correcting an image. It is useful if several images are going to be corrected.

Grid Descriptor contains information about a grid image that is used to learn the calibration. If the image has been calibrated previously, using the IMAQ Learn Calibration Template VI, this input is ignored and the previously defined grid descriptor is used. This is an optional input. This input contains the following information:

	X Step is the real-world distance between circle centers in the x direction.
	Y Step is the real-world distance between circle centers in the y direction.
	Unit is the units of X Step and Y Step.
	Threshold Range is the range of grayscale values in a grid image that represent the circles. This is the threshold range for detecting the centers of the circles. Lower value and Upper value must be between 0–255. Lower value is the lowest pixel value used during a manual threshold. The default is 1. Upper value is the highest pixel value used during a manual threshold. The default is 255.

error in (no error) describes the error status before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

	status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

Reference Points is the set of reference points to use in learning a calibration transformation. The minimum number of points is 4. If you connect Reference Points, a grid image is not required.

	Pixel Coordinates is the coordinates of the pixel reference points.
	Real World Coordinates is the measuring unit associated with the image.
	Unit is the measuring unit associated with the image. Choose from the following values: undefined (0) Units are undefined. angstrom (1) Units are measured in angstroms. micrometer (2) Units are measured in micrometers. millimeter (3) Units are measured in millimeters. centimeter (4) Units are measured in centimeters. meter (5) Units are measured in meters. kilometer (6) Units are measured in kilometers. microinch (7) Units are measured in microinches. inch (8) Units are measured in inches. feet (9) Units are measured in feet. nautical miles (10) Units are measured in nautical miles. standard miles (11) Units are measured in standard miles. steps (12) Units are measured in steps.

Calibration Axis Info defines a Reference Coordinate System for the real-world coordinates.

	Origin Pixel is the origin of the reference coordinate system, expressed in pixel units.
	Angle Relative to Horizontal (deg) is the angle of the x-axis of the real-world coordinate system, in relation to the horizontal. The horizontal is expressed by a row of circle centers.
	Axis Reference is defined as Direct or Indirect. Refer to Axis Type for more information.

Calibrated Image is the reference to the output image. This image contains the learned calibration information. Use this image to propagate the calibration information through your application.

The calibration information is associated with the image until the image is resized or disposed of. Use the IMAQ Write Image And Vision Info VI to save the calibration information to disk with the image. You can use the IMAQ Read Image And Vision InfoVI to retrieve the calibration information.

Quality Score is the quality score of the learning process between 0–1000. A quality of 1000 means that the chosen algorithm learned the feature points well. It does not necessarily reflect the absolute accuracy of the estimated calibration mapping.

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.