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WindowLevel Method
See Also  Example
Leadtools Namespace > RasterImage Class : WindowLevel Method



lowBit
Value indicating the low bit used for leveling. 0 <= RasterImage.LowBit <= RasterImage.HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).
highBit
Value indicating the high bit used for leveling. 0 <= RasterImage.LowBit <= RasterImage.HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).
palette
Optional 8-bit lookup table that can be used to implement a user defined conversion. For every intensity value between 0 and 2 raised to the power of (RasterImage.HighBit - RasterImage.LowBit + 1)-1 there should be a corresponding entry in the lookup table that contains a color. If palette is null (Nothing in Visual Basic), the conversion is a normal shift (right or left) and the painted image is 8-bit grayscale. If palette is not null (Nothing in Visual Basic), the painted image is a 24-bit image.
mode
Value indicating whether palette is used by the paint and image processing methods or only by the paint methods.
Sets up the paint or paint and image processing methods' window leveling options for this RasterImage

Syntax

Visual Basic (Declaration)  
Public Sub WindowLevel( _
   ByVal lowBit As Integer, _
   ByVal highBit As Integer, _
   ByVal palette() As RasterColor, _
   ByVal mode As RasterWindowLevelMode _
)
Visual Basic (Usage) Copy Code
Dim instance As RasterImage
Dim lowBit As Integer
Dim highBit As Integer
Dim palette() As RasterColor
Dim mode As RasterWindowLevelMode
 
instance.WindowLevel(lowBit, highBit, palette, mode)
C#  
public void WindowLevel( 
   int lowBit,
   int highBit,
   RasterColor[] palette,
   RasterWindowLevelMode mode
)
C++/CLI  
public:
void WindowLevel( 
   int lowBit,
   int highBit,
   array<RasterColor>^ palette,
   RasterWindowLevelMode mode
)

Parameters

lowBit
Value indicating the low bit used for leveling. 0 <= RasterImage.LowBit <= RasterImage.HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).
highBit
Value indicating the high bit used for leveling. 0 <= RasterImage.LowBit <= RasterImage.HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).
palette
Optional 8-bit lookup table that can be used to implement a user defined conversion. For every intensity value between 0 and 2 raised to the power of (RasterImage.HighBit - RasterImage.LowBit + 1)-1 there should be a corresponding entry in the lookup table that contains a color. If palette is null (Nothing in Visual Basic), the conversion is a normal shift (right or left) and the painted image is 8-bit grayscale. If palette is not null (Nothing in Visual Basic), the painted image is a 24-bit image.
mode
Value indicating whether palette is used by the paint and image processing methods or only by the paint methods.

Example

Visual Basic Copy Code
Public Sub WindowLevelExample()
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Load an image that has BottomLeft ViewPerspective
   Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP")

   ' Change the image to 16-bit grayscale
   Dim grayscaleCmd As GrayscaleCommand = New GrayscaleCommand(16)
   grayscaleCmd.Run(image)

   Dim minMaxBitsCmd As MinMaxBitsCommand = New MinMaxBitsCommand()
   minMaxBitsCmd.Run(image)

   Dim minMaxValuesCmd As MinMaxValuesCommand = New MinMaxValuesCommand()
   minMaxValuesCmd.Run(image)

   Dim lowBit As Integer = minMaxBitsCmd.MinimumBit
   Dim highBit As Integer = minMaxBitsCmd.MaximumBit

   Dim size As Integer = (1 << (image.HighBit - image.LowBit + 1))
   Dim palette As RasterColor() = New RasterColor(size - 1) {}

   ' fill the first half of the LUT with RED
   Dim x As Integer = 0
   Do While x < size / 2
      palette(x).R = 255
      palette(x).G = 0
      palette(x).B = 0
      palette(x).Reserved = 0
      x += 1
   Loop

   Dim minVal As Integer = minMaxValuesCmd.MinimumValue
   Dim maxVal As Integer = minMaxValuesCmd.MaximumValue

   ' Fill the rest with gray values
   x = (size \ 2)
   Do While x < size
      palette(x).R = Convert.ToByte(Math.Min(255, ((x - minVal) * 255 / (maxVal - minVal))))
      palette(x).G = palette(x).R
      palette(x).B = palette(x).R
      palette(x).Reserved = 0
      x += 1
   Loop
   image.WindowLevel(lowBit, highBit, palette, RasterWindowLevelMode.PaintAndProcessing)

   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_WindowLevel.BMP", RasterImageFormat.Bmp, 0)

   image.Dispose()
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C# Copy Code
public void WindowLevelExample() 
{ 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   // Load an image that has BottomLeft ViewPerspective 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP"); 
 
   // Change the image to 16-bit grayscale  
   GrayscaleCommand grayscaleCmd = new GrayscaleCommand(16); 
   grayscaleCmd.Run(image); 
 
   MinMaxBitsCommand minMaxBitsCmd = new MinMaxBitsCommand(); 
   minMaxBitsCmd.Run(image); 
 
   MinMaxValuesCommand minMaxValuesCmd = new MinMaxValuesCommand(); 
   minMaxValuesCmd.Run(image); 
 
   int lowBit = minMaxBitsCmd.MinimumBit; 
   int highBit = minMaxBitsCmd.MaximumBit; 
 
   int size = (1 << (image.HighBit - image.LowBit + 1)); 
   RasterColor[] palette = new RasterColor[size]; 
 
   // fill the first half of the LUT with RED 
   for(int x = 0; x < size / 2; x++) 
   { 
      palette[x].R = 255; 
      palette[x].G = 0; 
      palette[x].B = 0; 
      palette[x].Reserved = 0; 
   } 
 
   int minVal = minMaxValuesCmd.MinimumValue; 
   int maxVal = minMaxValuesCmd.MaximumValue; 
 
   // Fill the rest with gray values  
   for(int x = (size / 2); x < size; x++) 
   { 
      palette[x].R = Convert.ToByte(Math.Min(255, ((x - minVal) * 255 / (maxVal - minVal)))); 
      palette[x].G = palette[x].R; 
      palette[x].B = palette[x].R; 
      palette[x].Reserved = 0; 
   } 
   image.WindowLevel(lowBit, highBit, palette, RasterWindowLevelMode.PaintAndProcessing); 
 
   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_WindowLevel.BMP", RasterImageFormat.Bmp, 0); 
 
   image.Dispose(); 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

Remarks

This method is available in the (Document/Medical only) Toolkits.

Provides "on demand" window leveling for the paint methods and does not alter the image data. To convert the image data to a window leveled image, use WindowLevelCommand.

If RasterWindowLevelMode.PaintAndProcessing is specified, then all image processing methods will take the palette into account.

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 mode 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

For a version of this function that uses an 8-bit palette, see WindowLevelExt.

Saving Window-Leveled Images.

For more information, refer to Introduction to Image Processing With LEADTOOLS.

For more information, refer to Grayscale Images.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also