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ChangeViewPerspectiveCommand Class

Summary
Rotates and flips the image data as necessary to achieve the desired view perspective.
Syntax
C#
VB
Objective-C
C++
Java
public class ChangeViewPerspectiveCommand : RasterCommand 
Public Class ChangeViewPerspectiveCommand  
   Inherits RasterCommand 
@interface LTChangeViewPerspectiveCommand : LTRasterCommand 
public class ChangeViewPerspectiveCommand extends RasterCommand 
public ref class ChangeViewPerspectiveCommand : public RasterCommand   
Remarks

The ViewPerspective is the arrangement of pixels in the image. This command references image coordinates, which are often different from the display coordinates of an image.

Use this command to change the data and the ViewPerspective to simplify calculations that involve image coordinates. This method does not affect the image display. For more information, refer to Accounting for View Perspective.

Example

This example will load an image and then change its view perspective.

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
 
 
public void ChangeViewPerspectiveCommandExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
 
	// Load the source image from disk 
	RasterImage image = codecs.Load(srcFileName); 
 
	// Check the view perspective 
	Console.WriteLine("Original view perspective = {0}", image.ViewPerspective); 
 
	// If the view perspective is TopLeft, change to BottomLeft and vise versa 
	RasterViewPerspective viewPerspective = image.ViewPerspective; 
	if (viewPerspective == RasterViewPerspective.TopLeft) 
		viewPerspective = RasterViewPerspective.BottomLeft; 
	else 
		viewPerspective = RasterViewPerspective.TopLeft; 
 
	// Change the image view perspective 
	ChangeViewPerspectiveCommand command = new ChangeViewPerspectiveCommand(); 
	command.ViewPerspective = viewPerspective; 
	command.InPlace = true; 
 
	command.Run(image); 
 
	// Re-check the view perspective 
	Console.WriteLine("New view perspective = {0}", image.ViewPerspective); 
	Assert.IsTrue(image.ViewPerspective == viewPerspective); 
 
	// Clean up 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
 
Public Sub ChangeViewPerspectiveCommandExample() 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
 
   ' Load the source image from disk 
   Dim image As RasterImage = codecs.Load(srcFileName) 
 
   ' Check the view perspective 
   Console.WriteLine("Original view perspective = {0}", image.ViewPerspective) 
 
   ' If the view perspective is TopLeft, change to BottomLeft and vise versa 
   Dim viewPerspective As RasterViewPerspective = image.ViewPerspective 
   If viewPerspective = RasterViewPerspective.TopLeft Then 
      viewPerspective = RasterViewPerspective.BottomLeft 
   Else 
      viewPerspective = RasterViewPerspective.TopLeft 
   End If 
 
   ' Change the image view perspective 
   Dim command As ChangeViewPerspectiveCommand = New ChangeViewPerspectiveCommand() 
   command.ViewPerspective = viewPerspective 
   command.InPlace = True 
 
   command.Run(image) 
 
   ' Re-check the view perspective 
   Console.WriteLine("New view perspective = {0}", image.ViewPerspective) 
   Debug.Assert(image.ViewPerspective = viewPerspective) 
 
   ' Clean up 
   image.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class 
Requirements

Target Platforms

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