Table Of Contents

Advanced Setup Match Contour Pattern (G Dataflow)

Last Modified: October 26, 2017

Optimizes and fine-tunes advanced parameters used during the contour matching phase.

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match setup data in

String that contains information from the Setup Match Contour Pattern node.

If this input is not connected, the node uses default parameters for all unconfigured options.

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match options

Array of options to use during the matching phase.

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setup data item

Option to use during the matching phase.

Name Value Description
curve extraction mode 0

Specifies how the node identifies curves in the image. Set this option to 0 if you want the node to make no assumptions about the uniformity of objects in the image or the image background. Set this option to 1 if you want the node to assume that either the objects in the image or the image background consist of uniform pixel values. This option allows the node 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 node uses to identify curves in the image. Set this option to 0 to specify a fine filter width, set this option to 1 to specify the normal filter width, or set this option to 2 to specify contour tracing.

min curve length 3

Specifies the 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. 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 node identifies as a closed curve. If the gap is larger than this value, the node 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 node should identify both open and closed curves.

enable subpixel curve extraction 8

The node ignores this option.

enable correlation score 9

Specifies that the node 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 10

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 11

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

subpixel tolerance 12

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

initial match list length 13

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 14

Specifies whether the node 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 15

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

min match separation angle 16

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

min match separation scale 17

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

max match overlap 18

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 19

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 node returns matches with pixel or subpixel accuracy.

enable calibration support 20

Specifies whether or not the algorithm treat the inspection image as a calibrated image. Use the Set Siimple Calibration node or the Set Calibration Information node to calibrate the inspection image. The default value is TRUE.

enable contrast reversal 21

Specifies the contrast of the matches to search for. Set it to 0 to search for matches with the same contrast as the template. Set it to 1 to search for matches with the inverse contrast of the template. Set it to 2 to search for matches with the same and inverse contrast of the template. The default value is 0.

search strategy 22

Specifies the aggressiveness of the strategy used to find matches in the image. The default is 1. The following options are available.

  • conservative (0) —Specifies the geometric matching algorithm to use the largest possible amount of information from the image at the expense of slowing down the speed of the algorithm.
  • balanced (1)—Specifies the geometric matching algorithm to balance the amount of information from the image it uses with the speed of the algorithm.
  • aggressive (2)—Specifies the geometric matching algorithm to use a lower amount of information from the image, which allows the algorithm to run quickly but at the expense of accuracy.
refinement match factor 23

Specifies the factor applied to the number of matches requested to determine how many matches are refined in the pyramid stage. The default is 0, which specifies that the factor is determined internally by the Match Geometric Pattern node.

subpixel match factor 24

Specifies the factor applied to the number for matches requested to determine how many matches are used for the final (subpixel) stage. The default is 0, which specifies that the factor is determined internally by the Match Geometric Pattern node.

max refinement iterations 25

Specfies the number of iterations to perform to refine the curve.

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Item Value

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

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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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match setup data out

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

Connect this output to the Compute Contour Distances 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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