Table Of Contents

Setup Match Geometric Pattern (G Dataflow)

Last Modified: June 25, 2019

Sets parameters used during the matching process.

Run this node before using the Match Geometric Pattern node.

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match mode

Cluster identifying the conditions under which you want the node to find template matches.

Set the values for these conditions in the range settings array. Disabling any of these conditions or limiting their ranges decreases the search time.

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Rotation

Boolean that specifies when the node searches for occurrences of the template in the inspection image, allowing for template matches to be rotated.

TRUE Searches for occurrences of the template in the inspection image, allowing for template matches to be rotated.
FALSE Does not search for occurrences of the template in the inspection image.
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Scale

Boolean that specifies when the node searches for occurrences of the template in the inspection image, regardless of if possible matches are of a different size in the inspection image.

TRUE Searches for occurrences of the template in the inspection image, regardless of if possible matches are of a different size in the inspection image.
FALSE Does not search for occurrences of the template in the inspection image.

The default scale range is 75% to 125%.

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Occlusion

Boolean that specifies when the node searches for occurrences of the template in the inspection image, allowing for a specified percentage of the template to be occluded.

TRUE Searches for occurrences of the template in the inspection image, allowing for a specified percentage of the template to be occluded.
FALSE Does not search for occurrences of the template in the inspection image.

The default occlusion range is 0% to 25%.

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curve parameters

Cluster containing information about how curves are extracted from the inspection image during the match phase.

The Setup Match Geometric Pattern node ignores these settings if use learn curve parameters is set to TRUE.

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Extraction Mode

Input that specifies how the node identifies curves in the image.

Name Value Description
Normal 0

(Default) Select if you want the node to make no assumptions about the uniformity of objects in the image or the image background.

Uniform Regions 1

Select if you want the node to assume that either the objects in the image or the image background consist of uniform pixel values. This allows the node to more accurately calculate the external curves of the objects.

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Edge Threshold

Minimum contrast a seed point must have for it to begin a curve.

Valid values range from 1 to 255.

Default: 75

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Edge Filter Size

Width of the edge filter that the node uses to identify curves in the image.

Name Value Description
Fine 0

Sets to fine edge filter size.

Normal 1

(Default) Sets to normal edge filter size.

Contour Tracing 2

Sets to contour tracing edge filter size, which provides the best results for contour extraction but increases the time required to process the image.

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Min Length

Length, in pixels, of the smallest curve that you want the node to identify.

The node ignores any curves that have a length less than this value.

Default: 25

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Row Search Step Size

Distance, in the y direction, between the image rows that the algorithm inspects for curve seed points.

Valid values range from 1 to 255.

Default: 15

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Col Search Step Size

Distance, in the x direction, between the image columns that the algorithm inspects for curve seed points.

Valid values range from 1 to 255.

Default: 15

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Max Endpoint Gap

Maximum gap, in pixels, between the endpoints of a curve that the node identifies as a closed curve.

If the gap is larger than this value, the node identifies the curve as an open curve.

Default: 10

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Closed

Boolean value that specifies only closed curves are identified in the image.

TRUE Identifies only closed curves.
FALSE Identifies both open and closed curves.

Default: FALSE

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Subpixel

Boolean value that specifies if curve points are detected with subpixel accuracy.

TRUE Curve points are detected with subpixel accuracy.
FALSE Curve points are not detected with subpixel accuracy.

Default: FALSE

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subpixel accuracy?

Boolean value that specifies whether to calculate match locations with subpixel accuracy.

TRUE Calculates match locations with subpixel accuracy.
FALSE Does not calculate match locations with subpixel accuracy.

Default: FALSE

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use learn curve parameters

Boolean value that specifies whether to use the curve parameters from the Setup Learn Geometric Pattern node or the Advanced Setup Learn Geometric Pattern node to extract the target curves during the match phase.

TRUE Uses the curve parameters to extract the target curves during the match phase.
FALSE Does not use curve parameters to extract the target curves during the match phase.

Default: TRUE

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error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

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range settings

Array of the acceptable ranges for each match constraints option.

To decrease the search time, limit the range of these constraints as much as possible.

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Match Constraints

Match option whose values you want to constrain by the given range.

Name Value Description
Rotation Angle (degrees) 0

Set a range for this option to specify the angles at which you expect the node to find template matches in the inspection image. The node ignores this range if the Rotation is not enabled.

Scale Factor (%) 1

Set a range for this option to specify the sizes at which you expect the node to find template matches in the inspection image. The size is expressed as the following percentage: the size of the match divided by size of the template image, multiplied by 100. The node ignores this range if the Scale is not enabled.

Occlusion (%) 2

Set a range for this option to specify the amount of occlusion you expect for a match in the inspection image. Matches that have up to 50% occlusion are accurately detected. The node ignores this range if the Occlusion is not enabled.

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Min

Minimum value of the range for a given match constraint.

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Max

Maximum value of the range for a given match constraint.

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match geometric pattern setup data

String that contains information about the setup parameters for the matching phase.

Connect this output to the Match Geometric Pattern node or the Advanced Setup Match Geometric Pattern node.

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error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application


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