WindowLevelCommand Class

Converts a 12 or 16-bit grayscale image to an 8-bit grayscale or a 24-bit RGB image.
This class is available in Medical toolkits only.

Object Model

Syntax

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

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

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

'Usage
 
Dim instance As WindowLevelCommand

public sealed class WindowLevelCommand : Leadtools.ImageProcessing.IRasterCommand

function Leadtools.ImageProcessing.Core.WindowLevelCommand()

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

Remarks

This command supports 12 and 16-bit grayscale. Support for 12 and 16-bit grayscale images is available only in the Document/Medical toolkits.
This command does not support 32-bit grayscale images.
Leadtools.RasterByteOrder.Romm and Leadtools.RasterByteOrder.Gray are not supported by this command.

Only TIFF and DICOM file formats are capable of saving images that have been window-leveled. Images can be window-leveled by calling Leadtools.RasterImage.WindowLevel(System.Int32,System.Int32,Leadtools.RasterColor[],Leadtools.RasterWindowLevelMode) and specifying RasterWindowLevelMode.PaintAndProcessing for the flags parameter, by using the WindowLevelCommand or by loading an image from a file format that supports Window Leveling. If a window-leveled image is saved as any other file format, the image data will be converted before being saved. For more information, refer to Saving Window-Leveled Images.
See WindowLevelExtCommand for a version of this class using 16-bit lookup tables.
LEADTOOLS supports two types of LUTs for 10-16-bit grayscale images (8-bit LUT and 16-bit LUT). Typical grayscale image display and processing is done using an 8-bit LUT. But, you can also use a 16-bit LUT, which offers more precision. Some special video cards and monitors also support display of grayscale images using a 16-bit LUT.
For more information, refer to Introduction to Image Processing With LEADTOOLS.
For more information, refer to Grayscale Images.

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 WindowLevelCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

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

   ' Prepare the command
   'Change the image to 16-bit grayscale
   Dim graycommand As GrayscaleCommand = New GrayscaleCommand(16)
   Dim command As WindowLevelCommand = New WindowLevelCommand
   graycommand.Run(leadImage)

   Dim minValue As Integer = leadImage.MinValue
   Dim maxValue As Integer = leadImage.MaxValue
   Dim minBit As Integer = leadImage.LowBit
   Dim maxBit As Integer = leadImage.HighBit

   Dim Size As Integer = (1 << (maxBit - minBit + 1))
   Dim LookupTable() As RasterColor
   ReDim LookupTable(Size - 1)

   ' fill the first half of the LookupTable with RED.
   Dim x As Integer
   For x = 0 To Size \ 2 - 1
      LookupTable(x) = New RasterColor(255, 0, 0)
   Next

   ' fill the rest with gray values.
   For x = Size \ 2 To Size - 1
      Dim y As Byte = Convert.ToByte((x - minValue) * 255 / (maxValue - minValue))
      LookupTable(x) = New RasterColor(y, y, y)
   Next

   command.HighBit = maxBit
   command.LowBit = minBit

   command.LookupTable = LookupTable
   command.Order = RasterByteOrder.Bgr
   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 WindowLevelCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg"));

      // Prepare the command
      int x;
      byte y;
      int Size;
      RasterColor [] LookupTable;

      //Change the image to 16-bit grayscale
      GrayscaleCommand graycommand = new GrayscaleCommand(16);
      MinMaxBitsCommand MinMaxBits = new MinMaxBitsCommand();
      MinMaxValuesCommand MinMaxValues = new MinMaxValuesCommand();
      WindowLevelCommand command = new WindowLevelCommand();

      graycommand.Run(image);
      MinMaxBits.Run(image);
      MinMaxValues.Run(image);

      Size = (1 <<(MinMaxBits.MaximumBit - MinMaxBits.MinimumBit + 1));
      LookupTable = new Leadtools.RasterColor[Size];

      // fill the first half of the LookupTable with RED.
      for(x = 0; x < Size / 2; x++)
         LookupTable[x] = new Leadtools.RasterColor(255, 0, 0);

      // fill the rest with gray values.
      for(x = Size / 2; x < Size; x++)
      {
         y = (byte)((x - MinMaxValues.MinimumValue) * 255 / (MinMaxValues.MaximumValue - MinMaxValues.MinimumValue));
         LookupTable[x] = new Leadtools.RasterColor(y, y, y);
      }

      command.HighBit = MinMaxBits.MaximumBit;
      command.LowBit  = MinMaxBits.MinimumBit;
      command.LookupTable = LookupTable;
      command.Order = Leadtools.RasterByteOrder.Bgr;

      command.Run(image);

   }

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

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

   // Load the image
   var srcFileName = "Assets\\Image1.cmp";
   var processedImage;
   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) {
         var x;
         var y;
         var Size;
         var LookupTable = new Array();

         //Change the image to 16-bit grayscale
         var graycommand = new Leadtools.ImageProcessing.GrayscaleCommand(16);
         var MinMaxBits = new MinMaxBitsCommand();
         var MinMaxValues = new MinMaxValuesCommand();
         var command = new WindowLevelCommand();

         graycommand.run(image);
         MinMaxBits.run(image);
         MinMaxValues.run(image);
         
         Size = (1 <<(MinMaxBits.maximumBit - MinMaxBits.minimumBit + 1));
         
         // fill the first half of the LookupTable with RED.
         for(x = 0; x < Size / 2; x++)
            LookupTable[x] = Leadtools.RasterColorHelper.create(255, 0, 0);
         
         // fill the rest with gray values.
         for(x = Size / 2; x < Size; x++)
         {
            y = (x - MinMaxValues.minimumValue) * 255 / (MinMaxValues.maximumValue - MinMaxValues.minimumValue);
            LookupTable[x] = Leadtools.RasterColorHelper.create(y, y, y);
         }
         
         command.highBit = MinMaxBits.maximumBit;
         command.lowBit  = MinMaxBits.minimumBit;
         command.lookupTable = LookupTable;
         command.order = Leadtools.RasterByteOrder.bgr;
         
         command.run(image);
      }
   });
}

[TestMethod]
public async Task WindowLevelCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Prepare the command
   int x;
   byte y;
   int Size;
   RasterColor [] LookupTable;

   //Change the image to 16-bit grayscale
   GrayscaleCommand graycommand = new GrayscaleCommand(16);
   MinMaxBitsCommand MinMaxBits = new MinMaxBitsCommand();
   MinMaxValuesCommand MinMaxValues = new MinMaxValuesCommand();
   WindowLevelCommand command = new WindowLevelCommand();

   graycommand.Run(image);
   MinMaxBits.Run(image);
   MinMaxValues.Run(image);

   Size = (1 <<(MinMaxBits.MaximumBit - MinMaxBits.MinimumBit + 1));
   LookupTable = new Leadtools.RasterColor[Size];

   // fill the first half of the LookupTable with RED.
   for(x = 0; x < Size / 2; x++)
      LookupTable[x] = Leadtools.RasterColorHelper.Create(255, 0, 0);

   // fill the rest with gray values.
   for(x = Size / 2; x < Size; x++)
   {
      y = (byte)((x - MinMaxValues.MinimumValue) * 255 / (MinMaxValues.MaximumValue - MinMaxValues.MinimumValue));
      LookupTable[x] = Leadtools.RasterColorHelper.Create(y, y, y);
   }

   command.HighBit = MinMaxBits.MaximumBit;
   command.LowBit  = MinMaxBits.MinimumBit;
   command.LookupTable = LookupTable;
   command.Order = Leadtools.RasterByteOrder.Bgr;

   command.Run(image);

}

public void WindowLevelCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   int x;
   byte y;
   int Size;
   RasterColor[] LookupTable;
   //Change the image to 16-bit grayscale
   GrayscaleCommand graycommand = new GrayscaleCommand(16);
   MinMaxBitsCommand MinMaxBits = new MinMaxBitsCommand();
   MinMaxValuesCommand MinMaxValues = new MinMaxValuesCommand();
   WindowLevelCommand command = new WindowLevelCommand();

   graycommand.Run(image);
   MinMaxBits.Run(image);
   MinMaxValues.Run(image);

   Size = (1 << (MinMaxBits.MaximumBit - MinMaxBits.MinimumBit + 1));
   LookupTable = new Leadtools.RasterColor[Size];

   // fill the first half of the LookupTable with RED.
   for (x = 0; x < Size / 2; x++)
      LookupTable[x] = new Leadtools.RasterColor(255, 0, 0);

   // fill the rest with gray values.
   for (x = Size / 2; x < Size; x++)
   {
      y = (byte)((x - MinMaxValues.MinimumValue) * 255 / (MinMaxValues.MaximumValue - MinMaxValues.MinimumValue));
      LookupTable[x] = new Leadtools.RasterColor(y, y, y);
   }

   command.HighBit = MinMaxBits.MaximumBit;
   command.LowBit = MinMaxBits.MinimumBit;
   command.LookupTable = LookupTable;
   command.Order = Leadtools.RasterByteOrder.Bgr;

   command.Run(image);
   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}

Public Sub WindowLevelCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim x As Integer
   Dim y As Byte
   Dim Size As Integer
   Dim LookupTable As RasterColor()
   'Change the image to 16-bit grayscale
   Dim graycommand As GrayscaleCommand = New GrayscaleCommand(16)
   Dim MinMaxBits As MinMaxBitsCommand = New MinMaxBitsCommand()
   Dim MinMaxValues As MinMaxValuesCommand = New MinMaxValuesCommand()
   Dim command As WindowLevelCommand = New WindowLevelCommand()

   graycommand.Run(image)
   MinMaxBits.Run(image)
   MinMaxValues.Run(image)

   Size = (1 << (MinMaxBits.MaximumBit - MinMaxBits.MinimumBit + 1))
   LookupTable = New RasterColor(Size - 1) {}

   ' fill the first half of the LookupTable with RED.
   x = 0
   Do While x < Size / 2
      LookupTable(x) = New RasterColor(255, 0, 0)
      x += 1
   Loop

   ' fill the rest with gray values.
   x = Size / 2
   Do While x < Size
      y = CByte((x - MinMaxValues.MinimumValue) * 255 / (MinMaxValues.MaximumValue - MinMaxValues.MinimumValue))
      LookupTable(x) = New RasterColor(y, y, y)
      x += 1
   Loop

   command.HighBit = MinMaxBits.MaximumBit
   command.LowBit = MinMaxBits.MinimumBit
   command.LookupTable = LookupTable
   command.Order = RasterByteOrder.Bgr

   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