private static Line GetTriangleAltitude(PolygonalRoiTests.PolygonShape triangleShape, int indexAngle)
{
PointF point = PointF.Empty;
Vector.DistanceFromPointToLine(triangleShape[indexAngle], triangleShape[(indexAngle + 1) % 3], triangleShape[(indexAngle + 2) % 3], ref point);
return(new Line(triangleShape[indexAngle], point));
}
public void TestLengthMeasurementIsometricPixelAspectRatio()
{
// A
// c / \ b
// B---C
// a
// various lengths on an equilateral triangle figure
// these expected values were independently computed by hand
PolygonalRoiTests.PolygonShape triangleShape = PolygonalRoiTests.PolygonShape.Triangle;
Line sideA = GetTriangleSide(triangleShape, 0);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, sideA, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, sideA, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, sideA, 8, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, sideA, 8, 0.01, Units.Centimeters);
Line sideB = GetTriangleSide(triangleShape, 1);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, sideB, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, sideB, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, sideB, 8, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, sideB, 8, 0.01, Units.Centimeters);
Line sideC = GetTriangleSide(triangleShape, 2);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, sideC, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, sideC, 200);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, sideC, 8, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, sideC, 8, 0.01, Units.Centimeters);
// the altitude of these triangles in pixels can be computed normally by dropping a line perpendicular to the selected base
// when computing in centimetres (and thus adjusting for pixel aspect ratio), the altitude is actually the bisector in the
// triangle before adjusting for pixel aspect ratio - because these triangles are supposed to be equilateral, in which case
// the bisectors are also the altitudes.
Line altitudeA = GetTriangleAltitude(triangleShape, 0);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, altitudeA, 173);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, altitudeA, 173);
Line bisectorA = GetTriangleBisector(triangleShape, 0);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, bisectorA, 6.9241, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, bisectorA, 6.9241, 0.01, Units.Centimeters);
Line altitudeB = GetTriangleAltitude(triangleShape, 1);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, altitudeB, 173);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, altitudeB, 173);
Line bisectorB = GetTriangleBisector(triangleShape, 1);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, bisectorB, 6.9241, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, bisectorB, 6.9241, 0.01, Units.Centimeters);
Line altitudeC = GetTriangleAltitude(triangleShape, 2);
base.TestRoiLengthMeasurement(ImageKey.Aspect01, altitudeC, 173);
base.TestRoiLengthMeasurement(ImageKey.Aspect02, altitudeC, 173);
Line bisectorC = GetTriangleBisector(triangleShape, 2);
base.TestRoiLengthMeasurement(ImageKey.Aspect03, bisectorC, 6.9241, 0.01, Units.Centimeters);
base.TestRoiLengthMeasurement(ImageKey.Aspect04, bisectorC, 6.9241, 0.01, Units.Centimeters);
}
private static Line GetTriangleBisector(PolygonalRoiTests.PolygonShape triangleShape, int indexAngle)
{
return(new Line(triangleShape[indexAngle], Vector.Midpoint(triangleShape[(indexAngle + 1) % 3], triangleShape[(indexAngle + 2) % 3])));
}
private static Line GetTriangleSide(PolygonalRoiTests.PolygonShape triangleShape, int indexOppositeAngle)
{
return(new Line(triangleShape[(indexOppositeAngle + 1) % 3], triangleShape[(indexOppositeAngle + 2) % 3]));
}