IMAQ Setup Match Geometric Pattern VI

LabView NI Vision

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IMAQ Setup Match Geometric Pattern VI

Owning Palette: Searching and MatchingInstalled With: NI Vision Development Module

Sets parameters that are used during the matching process. Run this VI before using the IMAQ Match Geometric Pattern VI.

IMAQ Setup Match Geometric Pattern

Curve Parameters is a cluster containing information about how curves are extracted from the inspection image during the match phase.

Note The VI ignores the Curve Parameters settings if Use Learn Curve Parameters is set to TRUE.

Extraction Mode specifies how the VI identifies curves in the image. Choose from the following options:

Normal (0)	(Default) Select Normal if you want the VI to make no assumptions about the uniformity of objects in the image or the image background.
Uniform Regions (1)	Select 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 allows the VI to more accurately calculate the external curves of the objects.

Edge Threshold specifies the minimum contrast a seed point must have for it to be begin a curve. Valid values range from 1 to 360. The default value is 75.

Edge Filter Size specifies the width of the edge filter that the VI uses to identify curves in the image. The following options are available:

Fine (0)	Sets the Edge Filter Size to fine.
Normal (1)	(Default) Sets the Edge Filter Size to normal.

Min Length 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.

Row Search Step Size 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.

Col Search Step Size 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.

Max Endpoint Gap 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.

Closed 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.

Subpixel is ignored by the VI.

Match Mode is a cluster identifying the conditions under which you want the VI to find template matches. Set the values for these conditions in the Range Settings array.

Note Disabling any of these conditions or limiting their ranges decreases the search time.

	Rotation When enabled, the VI searches for occurrences of the template in the inspection image, allowing for template matches to be rotated.
	Scale When enabled, the VI searches for occurrences of the template in the inspection image regardless of whether possible matches are of a different size in the inspection image. The default scale range is 75% to 125%.
	Occlusion When enabled, the VI searches for occurrences of the template in the inspection image, allowing for a specified percentage of the template to be occluded. The default occlusion range is 0% to 25%.

Subpixel Accuracy determines whether to calculate match locations with subpixel accuracy. The default is FALSE.

Range Settings is an 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.

Match Constraints specifies the match option whose values you want to constrain by the given range. The following options are available:

Rotation Angle (degrees) (0)	Set a range for this option to specify the angles at which you expect the VI to find template matches in the inspection image. The VI 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 VI 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 VI 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. NI Vision can accurately detect matches that have up to 50% occlusion. The VI ignores this range if the Occlusion is not enabled.

Min is the minimum value of the range for a given Match Constraint.

Max is the maximum value of the range for a given Match Constraint.

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.

Use Learn Curve Parameters specifies whether to use the Curve Parameters from the IMAQ Setup Learn Geometric Pattern VI or the IMAQ Advanced Setup Learn Geometric Pattern VI to extract the target curves during the match phase. The default value is TRUE.

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

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.

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