ChangeViewPerspectiveCommand Class

Rotates and flips the image data as necessary to achieve the desired view perspective.

Object Model

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public class ChangeViewPerspectiveCommand : RasterCommand, IRasterCommand

'Declaration
 
Public Class ChangeViewPerspectiveCommand 
   Inherits RasterCommand
   Implements IRasterCommand

'Usage
 
Dim instance As ChangeViewPerspectiveCommand

public sealed class ChangeViewPerspectiveCommand : IRasterCommand

function Leadtools.ImageProcessing.ChangeViewPerspectiveCommand()

public ref class ChangeViewPerspectiveCommand : public RasterCommand, IRasterCommand

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

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

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:\Users\Public\Documents\LEADTOOLS Images"
End Class

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);
      Debug.Assert(image.ViewPerspective == viewPerspective);

      // Clean up
      image.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

RasterCommandExamples.prototype.ChangeViewPerspectiveCommandExample = function () {
    Tools.SetLicense();
    with (Leadtools) {
        with (Leadtools.Codecs) {

            var codecs = new RasterCodecs();
            var srcFileName = "Assets\\Image1.cmp";
            var image;

            // Load the source image from disk
            return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
                return codecs.loadAsync(LeadStreamFactory.create(loadFile), 24, CodecsLoadByteOrder.bgr, 1, 1)
            })
                .then(function (img) {
                    image = img;
                    // Check the view perspective
                    console.info("Original view perspective = ", image.viewPerspective);

                    // If the view perspective is TopLeft, change to BottomLeft and vise versa
                    var viewPerspective = image.viewPerspective;
                    if (viewPerspective == RasterViewPerspective.topLeft)
                        viewPerspective = RasterViewPerspective.bottomLeft;
                    else
                        viewPerspective = RasterViewPerspective.topLeft;

                    // Change the image view perspective
                    var command = new Leadtools.ImageProcessing.ChangeViewPerspectiveCommand();
                    command.viewPerspective = viewPerspective;
                    command.inPlace = true;

                    command.run(image);

                    // Re-check the view perspective
                    console.info("New view perspective = ", image.viewPerspective);
                    console.assert(image.viewPerspective === viewPerspective);

                    // Clean up
                    image.close();
                    codecs.close();
                });
        }
    }
}

[TestMethod]
public async Task ChangeViewPerspectiveCommandExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = @"Assets\Image1.cmp";

   // Load the source image from disk
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile), 24, CodecsLoadByteOrder.Bgr, 1, 1);

   // Check the view perspective
   Debug.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
   Debug.WriteLine("New view perspective = {0}", image.ViewPerspective);
   Assert.IsTrue(image.ViewPerspective == viewPerspective);

   // Clean up
   image.Dispose();
}

public void ChangeViewPerspectiveCommandExample(RasterImage image)
{
   RasterCodecs codecs = new RasterCodecs();
   // Check the view perspective
   Debug.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
   Debug.WriteLine("New view perspective = {0}", image.ViewPerspective);
   Debug.Assert(image.ViewPerspective == viewPerspective);

   // Clean up
   image.Dispose();
}

Public Sub ChangeViewPerspectiveCommandExample(ByVal image As RasterImage)
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Check the view perspective
   Debug.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
   Debug.WriteLine("New view perspective = {0}", image.ViewPerspective)
   Debug.Assert(image.ViewPerspective = viewPerspective)

   ' Clean up
   image.Dispose()
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

ChangeViewPerspectiveCommand Members
Leadtools.ImageProcessing Namespace