IMAQ Advanced Setup Match Geometric Pattern VI

LabView NI Vision

IMAQ Advanced Setup Match Geometric Pattern VI

Owning Palette: Pattern Matching AdvancedInstalled With: NI Vision Development Module

Optimizes and fine-tunes advanced parameters used during the matching phase. Execute this VI before the IMAQ Match Geometric Pattern VI. If you use the IMAQ Setup Match Geometric Pattern VI along with this VI, execute this VI after IMAQ Setup Match Geometric Pattern.

IMAQ Advanced Setup Match Geometric Pattern

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Match Geometric Pattern Setup Data In is a string that contains information from the IMAQ Setup Match Geometric Pattern VI. If this input is not connected, the VI uses default parameters for all unconfigured options.

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Advanced Geometric Match Options is an array of options to use during the matching phase.

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Setup Data Item determines the option you want to use during the matching phase. The following options are possible:

Curve Extraction Mode (0)

Specifies how the VI identifies curves in the image. Set this option to Normal if you want the VI to make no assumptions about the uniformity of objects in the image or the image background. Set this option to Uniform Regions if you want the VI to assume that either the objects in the image or the image background consist of uniform pixel values. This option allows the VI to more accurately calculate the external curves of the objects.

Curve Edge Threshold (1)

Specifies the minimum contrast an edge pixel must have for it to be considered part of a curve. Valid values range from 1 to 255.

Curve Edge Filter Size (2)

Specifies the width of the edge filter that the VI uses to identify curves in the image. Set this option to 0 to specify a fine filter width, or set the option to 1 to specify the normal filter width.

Min Curve Length (3)

Specifies the length, in pixels, of the smallest curve that you want the VI to identify. The VI ignores any curves that have a length less than this value. The default value is 25.

Curve Row Search Step Size (4)

Specifies the distance, in the y direction, between the image rows that the algorithm inspects for curve seed points. Valid values range from 1 to 255. The default value is 15.

Curve Col Search Step Size (5)

Specifies the distance, in the x direction, between the image columns that the algorithm inspects for curve seed points. Valid values range from 1 to 255. The default value is 15.

Curve Max Endpoint Gap (6)

Specifies the maximum gap, in pixels, between the endpoints of a curve that the VI identifies as a closed curve. If the gap is larger than this value, the VI identifies the curve as an open curve. The default value is 10.

Extract Closed Curves (7)

Specifies whether to identify only closed curves in the image. The default value is FALSE, which specifies that the VI should identify both open and closed curves.

Enable Subpixel Curve Extraction (8)

The VI ignores this option.

Min Features (9)

Specifies the minimum number of features the VI uses when matching. Set this option to 0 if you want the algorithm to use all of the features. The default value is 5.

Max Features (10)

Specifies the maximum number of features the VI uses to finalize a match. The default value is 5.

Enable Correlation Score (11)

Specifies that the VI should calculate the Correlation Score and return it for each match result. The default value is 1, which enables the Correlation Score.

Enable Subpixel Accuracy (12)

Determines whether to return the match results with subpixel accuracy. Set this option to 1 to enable subpixel accuracy. The default value is 0, which disables subpixel accuracy.

Subpixel Iterations (13)

Specifies the maximum number of incremental improvements used to refine matches using subpixel information. The minimum value for this option is 20.

Subpixel Tolerance (14)

Specifies the maximum amount of change, in pixels, between consecutive incremental improvements in the match position before the VI stops refining the match position. The default value is 0, which specifies that the VI should always use a number of refinements equal to Subpixel Iterations. If you provide values for both Subpixel Iterations and Subpixel Tolerance, the VI refines the match for, at most, Subpixel Iterations but may stop early if Subpixel Tolerance is satisfied.

Initial Match List Length (15)

Specifies the maximum size of the match list. The match list contains the regions in the inspection image that have the highest probability of containing a match. The minimum value for this option is 5. The default value is 200.

Enable Target Template Curve Score (16)

Specifies whether the VI should calculate the match curve to template curve score and return it for each match result. Set this option to 1 to enable the target template curve score. The default value is 0, which disables the target template curve score.

Min Match Separation Distance (17)

Specifies the minimum separation distance, in pixels, between the origins of two matches that have unique positions. The VI does not return matches that have the same position, scale, and angle. Set this value to -1 if you do not want the VI to use the position of a match to determine whether the match is unique. The default value is 20.

Min Match Separation Angle (18)

Specifies the minimum angular difference, in degrees, between two matches that have unique angles. The VI does not return matches that have the same position, scale, and angle. Set this value to -1 if you do not want the VI to use the angle of a match to determine whether the match is unique. The default value is 10.

Min Match Separation Scale (19)

Specifies the minimum difference in scale, expressed as a percentage, between two matches that have unique scales. The VI does not return matches that have the same position, scale, and angle. Set this value to -1 if you do not want the VI to use the scale of a match to determine whether the match is unique. The default value is 10.

Max Match Overlap (20)

Specifies the maximum amount of overlap, expressed as a percentage, allowed between the bounding rectangles of two matches. Set this value to -1 to ignore this option. The default value is 80.

Enable Coarse Result (21)

Specifies whether you want the algorithm to spend less time accurately estimating the location of a match. Set this value to 1 if you want to quickly determine whether a part is present in the inspection image without an accurate estimate of its position, angle, and scale. The default value is 0, which specifies that the VI returns matches with pixel or subpixel accuracy.

Smooth Contours (22)

Specifies whether or not smoothing be done on the contours of the inspection image before feature extraction. The default value is FALSE.

Enable Calibration Support (23)

Specifies whether or not the algorithm treat the inspection image as a calibrated image. Use the IMAQ Set Simple Calibration VI or the IMAQ Set Calibration Info VI to calibrate the inspection image. The default value is TRUE.

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Item Value is the value for the option you want to use during the matching phase.

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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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Match Geometric Pattern Setup Data Out is a string that contains information about the setup parameters for the matching phase. Connect this output to the IMAQ Match Geometric Pattern VI.

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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.