ApplyLinearVoiLookupTableCommand Class

Sets up the paint or paint and image processing methods window leveling options for a specific image through a linear transformation described by the window center and width. This class is available in the Document/Medical toolkits only.

Object Model

Syntax

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

public class ApplyLinearVoiLookupTableCommand : Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

'Declaration
 
Public Class ApplyLinearVoiLookupTableCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements Leadtools.ImageProcessing.IRasterCommand

'Usage
 
Dim instance As ApplyLinearVoiLookupTableCommand

public sealed class ApplyLinearVoiLookupTableCommand : Leadtools.ImageProcessing.IRasterCommand

function Leadtools.ImageProcessing.Core.ApplyLinearVoiLookupTableCommand()

public ref class ApplyLinearVoiLookupTableCommand : public Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

Remarks

This class sets up the paint or paint and image processing methods window leveling options for a specific image through a linear transformation described by the window center and width. In the DICOM world, this is referred to as "applying a linear VOI LookupTable (LookupTable)".
This class will remap the LookupTable used to display and process an image by applying the linear transformation described by the window center and window width. In the DICOM world this is referred to as applying a "linear VOI LookupTable (LookupTable)". The DICOM standard states:
"Window Center and Window Width specify a linear conversion from stored pixel values (after any Modality LookupTable or Rescale Slope and Intercept specified in the IOD have been applied) to values to be displayed. Window Center contains the input value that is the center of the window. Window Width contains the width of the window." Please see "VOI LookupTable (LookupTable) Module Attributes" in the DICOM standard for more details.
This class does not change the image data; it only updates the entries inside the image LookupTable.
It's recommended to always set the VoiLookupTableCommandFlags.UpdateMinMax flag.
In the DICOM world you must set VoiLookupTableCommandFlags.ReverseOrder flag if the photometric interpretation of the image is "MONOCHROME1", where the minimum grayscale value is intended to be displayed as white after any VOI gray scale transformations have been performed.
This class supports 12 and 16-bit grayscale. Support for 12 and 16-bit grayscale is available only in the Document/Medical toolkits.
This command does not support 32-bit grayscale images.

For more information, refer to Changing Brightness and Contrast.

In Silverlight and Windows Phone versions of LEADTOOLS, this image processing command will fail if the image data for the RasterImage object is stored internally using a Silverlight WriteableBitmap object. For more information, refer to Image Processing Command Limitations in Silverlight.

Example

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

Public Sub ApplyLinearVoiLookupTableCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE2.dcm"))

   ' Prepare the command
   Dim command As ApplyLinearVoiLookupTableCommand = New ApplyLinearVoiLookupTableCommand
   command.Flags = VoiLookupTableCommandFlags.None
   command.Center = 330.0
   command.Width = 600.0
   ' Apply "Abdomen T1" window-level , high bit is assumed 
   ' to be "11" and low bit "0. 
   command.Run(leadImage)

End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

public void ApplyLinearVoiLookupTableCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE2.dcm"));

      // Prepare the command
      ApplyLinearVoiLookupTableCommand command = new ApplyLinearVoiLookupTableCommand();
      command.Flags  = VoiLookupTableCommandFlags.None;
      command.Center = 330.0;
      command.Width  = 600.0;
      // Apply "Abdomen T1" window-level , high bit is assumed 
      // to be "11" and low bit "0. 
      command.Run(image);

   }

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

function ApplyLinearVoiLookupTableCommandExample()
{
   var codecs = new Leadtools.Codecs.RasterCodecs();
   codecs.throwExceptionsOnInvalidImages = true;

   // Load the image
   var srcFileName = "Assets\\Image2.dcm";
   return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
      return codecs.loadAsync(Leadtools.LeadStreamFactory.create(loadFile));
   }).then(function (image){
      // Prepare the command
      with (Leadtools.ImageProcessing.Core) {
         // Prepare the command
         var command = new ApplyLinearVoiLookupTableCommand();
         command.flags  = VoiLookupTableCommandFlags.none;
         command.center = 330.0;
         command.width  = 600.0;
         // Apply "Abdomen T1" window-level , high bit is assumed 
         // to be "11" and low bit "0. 
         command.run(image);
      }
   });
}

[TestMethod]
public async Task ApplyLinearVoiLookupTableCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\IMAGE2.dcm";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Prepare the command
   ApplyLinearVoiLookupTableCommand command = new ApplyLinearVoiLookupTableCommand();
   command.Flags  = VoiLookupTableCommandFlags.None;
   command.Center = 330.0;
   command.Width  = 600.0;
   // Apply "Abdomen T1" window-level , high bit is assumed 
   // to be "11" and low bit "0. 
   command.Run(image);

}

public void ApplyLinearVoiLookupTableCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   ApplyLinearVoiLookupTableCommand command = new ApplyLinearVoiLookupTableCommand();
   command.Flags = VoiLookupTableCommandFlags.None;
   command.Center = 330.0;
   command.Width = 600.0;
   // Apply "Abdomen T1" window-level , high bit is assumed 
   // to be "11" and low bit "0. 
   command.Run(image);
   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}

Public Sub ApplyLinearVoiLookupTableCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim command As ApplyLinearVoiLookupTableCommand = New ApplyLinearVoiLookupTableCommand()
   command.Flags = VoiLookupTableCommandFlags.None
   command.Center = 330.0
   command.Width = 600.0
   ' Apply "Abdomen T1" window-level , high bit is assumed 
   ' to be "11" and low bit "0. 
   command.Run(image)
   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   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

ApplyLinearVoiLookupTableCommand Members
Leadtools.ImageProcessing.Core Namespace
Changing Brightness and Contrast
ApplyVoiLookupTableCommand Class
Leadtools.ImageProcessing.Color.RemapIntensityCommand
ApplyModalityLookupTableCommand Class
ApplyLinearModalityLookupTableCommand Class
Leadtools.ImageProcessing.Color.AdjustTintCommand
Leadtools.ImageProcessing.Color.GammaCorrectExtendedCommand