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GetTransformationParameters Method

Computes the rotation angle, XY scaling, and XY translation of the transformed image with comparison to the reference image. These are the transformations that would have to be performed to the reference image to have it match the current image. This method is available in the Document/Medical Toolkits.
+ (nullable LTTransformationParameters *)getTransformationParameters:(LTRasterImage *)image 
                                                     referencePoints:(nullable NSArray<NSValue *> *)referencePoints /*LeadPoint*/ 
                                                   transformedPoints:(nullable NSArray<NSValue *> *)transformedPoints /*LeadPoint*/ 
                                                               error:(NSError **)error 
public static TransformationParameters getTransformationParameters( 
   RasterImage image, 
   LeadPoint[] referencePoints, 
   LeadPoint[] transformedPoints 
def GetTransformationParameters(self,image,] referencePoints,] transformedPoints): 


RasterImage object that references the transformed image.

Pointer to an array of reference points. These points represent the center of mass points for the registration marks in the reference image. You have to provide this information.

Pointer to an array of transformed points. These points are the center of mass points in the image. You have to provide this information.

Return Value


  • This method detects transformation parameters of the transformed image by comparing it with the reference image. The number of reference and detected points must be three.
  • Use GetRegistrationMarksCenterMass to fill the referencePoints array with the points representing the center of masses for each of the reference marks from the reference image.
  • Fill the transformedPoints array by performing the following steps:
  • The properties of TransformationParameters which are: XTranslation, YTranslation, Angle, XScale and YScale are internally divided by 100. For example, an Angle of 500 would mean to rotate the image 5 degrees clockwise.
  • The results of this method must be sent without any modification to the ApplyTransformationParameters method in order to correct the image.
  • If you want to correct the image yourself, you have to perform the inverse operations in this order:
  • If you simply want to automatically straighten the image, use the DeskewCommand.
  • This method supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
  • This command does not support signed images.

For more information, refer to Detecting Registration Marks.


This example computes the translation parameters. The example makes the assumption that you have saved the position of the registration marks of the reference image in a file. You should modify this example and replace the manual assignment of the rmData with your own code to load the reference registration mark data before testing this example.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
public void GetTransformationParametersExample() 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "RGSRef.cmp")); 
   // Prepare the command 
   SearchRegistrationMarksCommandData[] rmData = new SearchRegistrationMarksCommandData[3]; 
   rmData[0] = new SearchRegistrationMarksCommandData(); 
   rmData[0].Rectangle = new LeadRect(680, 20, 941 - 680, 218 - 20); 
   rmData[0].MarkDetectedPoints = new LeadPoint[1]; 
   rmData[0].Width = 31; 
   rmData[0].Height = 29; 
   rmData[0].Type = RegistrationMarkCommandType.TShape; 
   rmData[0].MinimumScale = 90; 
   rmData[0].MaximumScale = 110; 
   rmData[0].SearchMarkCount = 1; 
   rmData[1] = new SearchRegistrationMarksCommandData(); 
   rmData[1].Rectangle = new LeadRect(665, 790, 899 - 665, 961 - 790); 
   rmData[1].MarkDetectedPoints = new LeadPoint[1]; 
   rmData[1].Width = 31; 
   rmData[1].Height = 29; 
   rmData[1].Type = RegistrationMarkCommandType.TShape; 
   rmData[1].MinimumScale = 90; 
   rmData[1].MaximumScale = 110; 
   rmData[1].SearchMarkCount = 1; 
   rmData[2] = new SearchRegistrationMarksCommandData(); 
   rmData[2].Rectangle = new LeadRect(7, 1073, 298 - 7, 1246 - 1073); 
   rmData[2].MarkDetectedPoints = new LeadPoint[1]; 
   rmData[2].Width = 31; 
   rmData[2].Height = 29; 
   rmData[2].Type = RegistrationMarkCommandType.TShape; 
   rmData[2].MinimumScale = 90; 
   rmData[2].MaximumScale = 110; 
   rmData[2].SearchMarkCount = 1; 
   SearchRegistrationMarksCommand command1 = new SearchRegistrationMarksCommand(rmData); 
   if ((rmData[2].MarkDetectedCount != 1) || (rmData[1].MarkDetectedCount != 1) || (rmData[0].MarkDetectedCount != 1)) 
   LeadPoint[] original = 
      new LeadPoint(81400, 11300), 
      new LeadPoint(78600, 87400), 
      new LeadPoint(14300, 115400) 
   LeadPoint[] detected = 
   //Find center of mass for detected registration marks in the transformed image 
   LeadPoint[] transformed = CoreUtilities.GetRegistrationMarksCenterMass(image, detected); 
   //Find transformation parameters 
   TransformationParameters parameters = CoreUtilities.GetTransformationParameters(image, original, transformed); 
   //Apply transformation parameters to correct the image 
   ApplyTransformationParametersCommand applyCommand = new ApplyTransformationParametersCommand(parameters.XTranslation, parameters.YTranslation, parameters.Angle, parameters.XScale, parameters.YScale, 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 

Target Platforms

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Leadtools.ImageProcessing.Core Assembly

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.