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Calibrate Method

Sets the ruler calibration scale.
- (void)calibrate:(LeadLengthD)sourceLength sourceUnit:(LTAnnUnit)sourceUnit destinationLength:(LeadLengthD)destinationLength destinationUnit:(LTAnnUnit)destinationUnit NS_SWIFT_NAME(calibrate(sourceLength:sourceUnit:destinationLength:destinationUnit:)); 
public void calibrate( 
   LeadLengthD sourceLength, 
   AnnUnit sourceUnit, 
   LeadLengthD destinationLength, 
   AnnUnit destinationUnit 


Known source length value

Units of  sourceLength

What the destination length must be

Units of  destinationUnit


This method will use the parameters to calculate a new value for CalibrationScale. This value is used afterwards by all the existing ruler and new ruler objects created in this container.

The value of destinationUnit is set into CalibrationUnit and will be used as the default unit for all new ruler objects created in this container after this method has been called.

Calibrating a ruler means assigning a specific length to it. For example, on a digital X-ray of a hand, you may draw an annotation ruler object along one of the fingers. You know that this distance is supposed to be exactly 6.5 cm. Using the new calibration functionality you can calibrate this ruler, all existing rulers, and all newly created rulers so that they would precisely measure this distance to be 6.5 cm. This is accomplished by first drawing a ruler on the container till it matches exactly the length of the finger - ignoring the values shown - then using Calibrate as shown in the example.

Use AnnPolyRulerObject.Calibrate to set individual calibration values for a single ruler.


This example will draw a ruler with a length that is assumed is 6.5cm, it then uses Calibrate to set the mapper calibration scale.

using Leadtools.Annotations.Engine; 
public void AnnContainerMapper_Calibrate() 
   // Add a ruler with a length of 1 inch to the container 
   AnnContainer container = new AnnContainer(); 
   double inch = 720; 
   AnnPolyRulerObject rulerObj = new AnnPolyRulerObject(); 
   rulerObj.Points.Add(LeadPointD.Create(1 * inch, 1 * inch)); 
   rulerObj.Points.Add(LeadPointD.Create(2 * inch, 1 * inch)); 
   rulerObj.Stroke = AnnStroke.Create(AnnSolidColorBrush.Create("Red"), LeadLengthD.Create(1)); 
   rulerObj.ShowGauge = true; 
   rulerObj.ShowTickMarks = true; 
   rulerObj.MeasurementUnit = AnnUnit.Inch; 
   // Show the ruler 
   Debug.WriteLine("Ruler to calibrate, length is 1 inch"); 
   // Get the length of the ruler 
   LeadPointD point1 = rulerObj.Points[0]; 
   LeadPointD point2 = rulerObj.Points[1]; 
   double length = Math.Sqrt(Math.Pow(Math.Abs(point2.X - point1.X), 2) + Math.Pow(Math.Abs(point2.Y - point1.Y), 2)); 
   // Calibrate the container mapper 
      LeadLengthD.Create(length),   // Source length 
      AnnUnit.Unit,                       // Source unit (container units) 
      LeadLengthD.Create(6.5),      // Destination length 
      AnnUnit.Centimeter);                // Destination unit  
   // Use the Centimeters as the measurement unit in the ruler 
   rulerObj.MeasurementUnit = AnnUnit.Centimeter; 
   // Now rulerObj should show 6.5 Centimeter as its length 
   Debug.WriteLine("Calibrated, length is 6.5 cm"); 

Target Platforms

Help Version 22.0.2023.7.31
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Leadtools.Annotations.Engine Assembly

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.