F_VN_MatchContours1vsNExp

Compare a reference contour with multiple other contours using the Hu moment invariants (and optionally further aspects). Returns a sorted list of best matches. (expert function)

Syntax

Definition:

FUNCTION F_VN_MatchContours1vsNExp : HRESULT
VAR_INPUT
    ipRefContour            : ITcVnContainer;
    ipContours              : ITcVnContainer;
    ipMatchIndexes          : Reference To  ITcVnContainer;
    ipDissimilarities       : Reference To  ITcVnContainer;
    fDissimilarityThreshold : LREAL;
    eComparisonMethod       : ETcVnContoursMatchComparisonMethod;
    fAreaFactor             : LREAL;
    fAbsPositionFactor      : LREAL;
    hrPrev                  : HRESULT;
END_VAR

Inputs

Name	Type	Description
ipRefContour	ITcVnContainer	Reference contour (ContainerType_Vector_TcVnPoint2_DINT or ContainerType_Vector_TcVnPoint2_REAL; The elements of this container are the points of the contour)
ipContours	ITcVnContainer	Collection of multiple contours (CTcVnContainer_Vector_Vector_TcVnPoint2_DINT)
ipMatchIndexes	Reference To ITcVnContainer	Returns the indexes of the best matches (CTcVnContainer_Vector_ULINT; sorted, first element is best match, i.e. has lowest dissimilarity)
ipDissimilarities	Reference To ITcVnContainer	Returns the computed dissimilarities of the best matches (CTcVnContainer_Vector_LREAL; Optional, set to 0 if not required; sorted corresponding to ipMatchIndexes)
fDissimilarityThreshold	LREAL	Neglect irrelevant matches, i.e. dissimilarity > fDissimilarityThreshold
eComparisonMethod	ETcVnContoursMatchComparisonMethod	Method used for comparing the Hu moment invariants of the contours
fAreaFactor	LREAL	If > 0, the relative area difference between contours is scaled by this factor and added to the computed dissimilarity
fAbsPositionFactor	LREAL	If > 0, the absolute position difference between contours (i.e. the coordinates of the geometric contour centers) is scaled by this factor and added to the computed dissimilarity
hrPrev	HRESULT	HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.)

Return value

HRESULT

Required License

TC3 Vision Matching

System Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT V3.1. 4024.44 or later	PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU	Tc3_Vision