IMAQ Convert Pixel to Real World VI

LabView NI Vision

IMAQ Convert Pixel to Real World VI

Owning Palette: CalibrationInstalled With: NI Vision Development Module

Transforms pixel coordinates to real-world coordinates, according to the calibration information contained in the image. Calibration information is attached to this image by the IMAQ Learn Calibration Template VI, the IMAQ Set Simple Calibration VI, or the IMAQ Set Calibration Info VI.

Examples

IMAQ Convert Pixel to Real World

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Calibrated Image is the reference to the input image that has calibration information attached to it.

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Pixel Coordinates is a cluster of pixel coordinates to convert to real-world coordinates.

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Array of Pixel Coordinates is an array of pixel coordinate clusters to convert to real-world coordinates.

Note  If both Pixel Coordinates and Array of Pixel Coordinates are connected, the VI uses Array of Pixel Coordinates.
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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.

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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.

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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.

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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.

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Valid Coordinates returns TRUE if the transformed coordinate lies inside the Corrected Image Learn ROI of the IMAQ Learn Calibration Template VI. In the case of a simple calibration or a corrected image, Valid Coordinates is always TRUE. If one of the point coordinates is defined outside the ROI learned for calibration, this output is set to FALSE.

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Calibrated Image (duplicate) is a reference to the output image. This image is identical to the input Calibrated Image.

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Real World Coordinates returns a cluster of real-world point coordinates that correspond to the points specified by Point Coordinates.

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Array of Real World Coordinates is an array of real-world point coordinates corresponding to the array of pixel coordinates specified by Array of Pixel Coordinates.

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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.

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status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.

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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.

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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.

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Array of Valid Coordinates is an array of Boolean values specifying whether each transformation of the Array of Pixel Coordinates is valid, according to the region selected in the Corrected Image Learn ROI of the IMAQ Learn Calibration Template VI. Depending on which areas of the image were calibrated, not all pixel positions can be converted to real-world coordinates.

Examples

Refer to the following for examples that use this VI.

  • LabVIEW\examples\Vision\2. Functions\Calibration\Simple Calibration Example.vi

  • LabVIEW\examples\Vision\2. Functions\Calibration\Perspective Calibration Example.vi