MeasureMinEdgeDistance
Measure the minimum distance within the specified search window between 2 edges.
Can use available TwinCAT Job Tasks for executing parallel code regions.
Can return partial results when canceled by Watchdog.
Syntax
Definition:
HRESULT MeasureMinEdgeDistance(
HRESULT hrPrev,
ITcVnImage* ipSrcImage,
float& fMinDistance,
TcVnPoint2_REAL& aStartPoint,
TcVnPoint2_REAL& aEndPoint,
ETcVnEdgeDirection eEdgeDirection,
float fMinStrength,
ULONG nSearchLines,
TcVnPoint2_REAL& aPoint1,
TcVnPoint2_REAL& aPoint2,
float fSearchLineDist = 1,
ULONG nMaxThickness = 10,
bool bInvertSearchDirection = false,
float fSearchGap = 0,
ULONG nSubpixelsIterations = 10,
float fApproxPrecision = 0.001f,
ETcVnEdgeDetectionAlgorithm eAlgorithm = EDA_INTERPOLATION,
ITcVnContainer** pipEdgePoints1 = nullptr,
ITcVnContainer** pipEdgePoints2 = nullptr,
float fRangeCutoffFactor = 0.135f
)Parameters
|
Name |
Type |
Default |
Description |
|---|---|---|---|
|
hrPrev |
|
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) | |
|
ipSrcImage |
|
Source image (1 channel) | |
|
fMinDistance |
float& |
|
Returns the minimum distance between the detected edges |
|
aStartPoint |
|
Position from which to start the search process (in the direction of aEndPoint) | |
|
aEndPoint |
|
Position where the search process ends | |
|
eEdgeDirection |
|
Specification of the edge direction from aStartPoint to aEndPoint to search for | |
|
fMinStrength |
float |
|
Specification of the minimum strength (intensity difference) of the edge to search for |
|
nSearchLines |
ULONG |
|
Width of the search window, i.e. the number of search lines (1, 3, 5, 7, ...), centered around the line specified by aStartPoint and aEndPoint |
|
aPoint1 |
|
Returns the point on the edge near aStartPoint, for which the minimum distance is achieved | |
|
aPoint2 |
|
Returns the point on the edge near aEndPoint, for which the minimum distance is achieved | |
|
fSearchLineDist |
float |
1 |
Distance between the search lines in pixels (> 0) |
|
nMaxThickness |
ULONG |
10 |
Specification of the maximum thickness of the edge to search for, which means fMinStrength must be reached within nMaxThickness pixels |
|
bInvertSearchDirection |
bool |
false |
If true, the search starts from the center point between aStartPoint and aEndPoint in both directions |
|
fSearchGap |
float |
0 |
Optional width of a gap (>= 0, centered between aStartPoint and aEndPoint), that is neglected for searching edges (can reduce execution time). The 2 edges to search for must be on different sides of the gap. |
|
nSubpixelsIterations |
ULONG |
10 |
Specifies the number of subpixels (for INTERPOLATION, 10 - 20 usually is sufficient) or maximum number of iterations for optimizing the parameters (for APPROX_ERF and APPROX_GAUSSIAN, 50 - 100 usually is sufficient) |
|
fApproxPrecision |
float |
0.001f |
Specifies the approximation precision for APPROX_ERF and APPROX_GAUSSIAN (0.001 usually is sufficient, unused for INTERPOLATION) |
|
eAlgorithm |
EDA_INTERPOLATION |
Selection of the edge detection algorithm | |
|
pipEdgePoints1 |
nullptr |
Returns the detected edge points of the edge near aStartPoint (optional, set to 0 if not required; ContainerType_Vector_TcVnPoint2_REAL) | |
|
pipEdgePoints2 |
nullptr |
Returns the detected edge points of the edge near aEndPoint (optional, set to 0 if not required; ContainerType_Vector_TcVnPoint2_REAL) | |
|
fRangeCutoffFactor |
float |
0.135f |
Relative edge strength factor to cut off the range of pixels used for approximation. Negative numbers are valid to include noise, i.e. intensity differences in the other direction. At most nMaxThickness pixels are used in each direction. |
Return valueRequired License
TC3 Vision Metrology 2D