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WindowLevelCommand Class
See Also  Members   Example 
Leadtools.ImageProcessing.Core Namespace : 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.

Syntax

Visual Basic (Declaration) 
Public Class WindowLevelCommand 
   Inherits RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As WindowLevelCommand
C# 
public class WindowLevelCommand : RasterCommand, IRasterCommand 
C++/CLI 
public ref class WindowLevelCommand : public RasterCommand, IRasterCommand 

Example

Run the WindowLevelCommand on an image.

Visual BasicCopy Code
Public Sub WindowLevelCommandExample()
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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)

   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void WindowLevelCommandExample() 
{ 
   // Load an image 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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); 
 
   RasterCodecs.Shutdown(); 
}

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.
Only TIFF and DICOM file formats are capable of saving images that have been window-leveled. Images can be window-leveled by calling WindowLevel 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.
For more information, refer to Introduction to Image Processing With LEADTOOLS.
For more information, refer to Grayscale Images.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Core.WindowLevelCommand

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also