Gauge Types

Point Gauge

• Description: the point gauge finds points along a line probe segment that crosses the edges as specified by the measurement parameters.

• Nominal shape: a line segment (ELine ^{.NET Python}).

  • Use EPointGauge::GetNominalLine ^{.NET Python} to set the nominal line .

• Measured shape: a point set (EPointSet ^{.NET Python}).

  • Use EPointGauge::GetMeasuredPointSet ^{.NET Python} to get the measured set of points.

  • Use EPointSet::GetPoint ^{.NET Python} to get a measured point.

  • Use EPointSet::GetPoints ^{.NET Python} to get all the points.

Example of point gauges. On the left, both black to white and white to black transitions are detected. On the right, only black to white transitions are detected.

Line Gauge

• Description: the line gauge finds a line segment that follows an edge as specified by the measurement parameters.

• Nominal shape: a line segment (ELine ^{.NET Python}).

  • Use ELineGauge::GetNominal ^{.NET Python} to set the nominal line.

• Measured shape: a line segment (ELine ^{.NET Python})

  • Use ELineGauge::GetMeasuredLine ^{.NET Python} to get the measured line.

• Specific parameters:

  • Set ELineGauge::GetKnownAngle ^{.NET Python} to true to fix the slope of the line.

Example of a line gauge.

Rectangle Gauge

• Description: the rectangle gauge finds a rectangle that fits edges of the image as specified by the measurement parameters.

• Nominal shape: a rectangle (ERectangle ^{.NET Python}).

  • Use ERectangleGauge::GetNominal ^{.NET Python} to set the nominal rectangle .

• Measured shape: a rectangle (ERectangle ^{.NET Python}).

  • Use ERectangleGauge::GetMeasuredRectangle ^{.NET Python} to get the measured rectangle.

• Specific parameters:

  • Use ERectangleGauge::GetActiveEdges ^{.NET Python} to set the edge to fit to the image.

    The active edges of the rectangles are a combination of the value of the enumerate ERectangleGaugeEdge ^{.NET Python} (Left, Right, Bottom, Top).

  • Set ERectangleGauge::GetKnownAngle ^{.NET Python} to true to fix the orientation of the rectangle.

Example of a rectangle gauge.

Circle Gauge

• Description: the circle gauge finds a circle that fits edges of the image as specified by the measurement parameters.

• Nominal shape: a circle (ECircle ^{.NET Python})

  • Use ECircleGauge::GetNominal ^{.NET Python} to set the nominal line.

• Measured shape: a circle (ECircle ^{.NET Python})

  • Use ECircleGauge::GetMeasuredCircle ^{.NET Python} to get the measured circle.

Example of a circle gauge.

Wedge Gauge

• Description: the wedge gauge finds a wedge that fits edges of the image as specified by the measurement parameters.

• Nominal shape: a wedge (EWedge ^{.NET Python})

  • Use EWedgeGauge::GetNominal ^{.NET Python} to set the nominal wedge.

• Measured shape: a wedge (EWedge ^{.NET Python})

  • Use EWedgeGauge::GetMeasuredWedge ^{.NET Python} to get the measured wedge.

• Specific parameters:

  • Use EWedgeGauge::GetActiveEdges ^{.NET Python} to set the edge to fit to the image.

    The active edges of the wedge are a combination of the value of the enumerate EWedgeGaugeEdge ^{.NET Python}:

    • EWedgeGaugeEdge_Inner: inner circle edge.

    • EWedgeGaugeEdge_Outer: outer circle edge.

    • EWedgeGaugeEdge_Origin: segment linking the inner and outer edge at the EWedge::GetAngle ^{.NET Python}.

    • EWedgeGaugeEdge_End: segment linking the inner and outer edge at EWedge::GetAngle ^{.NET Python} and EWedge::GetAmplitude ^{.NET Python}.

Example of a wedge gauge.

Polygon Gauge

In orange, the closed or open polygon gauge and, in green, the measured transition points

• Description: the polygon gauge finds a polygon that fits edges of the image as specified by the measurement parameters.

• Nominal shape: a polygon (EPolygon ^{.NET Python})

  • Use EPolygonGauge::GetNominal ^{.NET Python} to set the nominal polygon.

• Measured shape: a polygon (EPolygon ^{.NET Python})

  • Use EPolygonGauge::GetMeasuredPolygon ^{.NET Python} to get the measured polygon.

  • When using the global measurement mode, the nominal polygon is transformed using an isotropic affine transform:

    • Use EPolygonGauge::GetMeasuredPolygonTransformation ^{.NET Python} to get the EFrame ^{.NET Python} object corresponding to this transformation.

    • Scaling is only considered if EPolygonGauge.EnableScaling is true.

    • Use EPolygonGauge::GetMeasuredOffset ^{.NET Python}, EPolygonGauge::GetMeasuredScale ^{.NET Python} and EPolygonGauge::GetMeasuredAngle ^{.NET Python} to directly get the offset, scale and angle of the transformation.

• Specific parameters:

  The measurement mode: EPolygonGauge::GetMeasurementMode ^{.NET Python}

  • In the mode EPolygonMeasurementMode_Global ^{.NET Python}, the polygon is rigid and the measured polygon is an isotropic affine transformation of the nominal polygon.

    • The position, orientation and optionally the scale of the polygon are adjusted to fit the measured points.

    • By default, the measurement mode is EPolygonMeasurementMode_Global ^{.NET Python}.

    • If a scaling is required, you must enable it with EPolygonGauge::GetEnableScaling ^{.NET Python}.

    Note

    The global measurement succeeds only if all the lines of the polygon can be fitted. If the measurement fails, try to simplify your polygon.

    

    The Global measurement mode: the measured polygon is a translation and a rotation of the input polygon

  • In the mode EPolygonMeasurementMode_Edge ^{.NET Python}, the edges of the polygon are measured independently.

    • The result is a new polygon composed of each of the nominal edge fitted to the image.

    • The number of edges of the measured polygon is the same as the nominal polygon.

    

    The input polygon (blue) and the fitted polygon (green)

  • In the mode EPolygonMeasurementMode_Point ^{.NET Python}, the measured polygon edges are sampled to fit closely to all the measured points.

    • The measured polygon is simplified using a filtering threshold (EBaseGauge::GetFilteringThreshold ^{.NET Python}) to reduce the number of edges while keeping the shape of the object.

    • The measured number of edges depends on the geometry of the contour of the object and on the filtering threshold.

    

    A polygon gauge with a single edge produces a measured polygon that follows the contour of the object

    Depending on the filtering threshold, the number of vertices is reduced.