WindowLevelFillLookupTable Method

Fills the user-allocated 8-bit LUT with values ranging between the startColor and endColor colors according to the selected LUT type.

Syntax

C#
Visual Basic
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

public static void WindowLevelFillLookupTable( 
   RasterColor[] lookupTable,
   RasterColor startColor,
   RasterColor endColor,
   int low,
   int high,
   int lowBit,
   int highBit,
   int minValue,
   int maxValue,
   int factor,
   RasterPaletteWindowLevelFlags flags
)

'Declaration
 
Public Shared Sub WindowLevelFillLookupTable( _
   ByVal lookupTable() As RasterColor, _
   ByVal startColor As RasterColor, _
   ByVal endColor As RasterColor, _
   ByVal low As Integer, _
   ByVal high As Integer, _
   ByVal lowBit As Integer, _
   ByVal highBit As Integer, _
   ByVal minValue As Integer, _
   ByVal maxValue As Integer, _
   ByVal factor As Integer, _
   ByVal flags As RasterPaletteWindowLevelFlags _
)

'Usage
 
Dim lookupTable() As RasterColor
Dim startColor As RasterColor
Dim endColor As RasterColor
Dim low As Integer
Dim high As Integer
Dim lowBit As Integer
Dim highBit As Integer
Dim minValue As Integer
Dim maxValue As Integer
Dim factor As Integer
Dim flags As RasterPaletteWindowLevelFlags
 
RasterPalette.WindowLevelFillLookupTable(lookupTable, startColor, endColor, low, high, lowBit, highBit, minValue, maxValue, factor, flags)

public static void WindowLevelFillLookupTable( 
   RasterColor[] lookupTable,
   RasterColor startColor,
   RasterColor endColor,
   int low,
   int high,
   int lowBit,
   int highBit,
   int minValue,
   int maxValue,
   int factor,
   RasterPaletteWindowLevelFlags flags
)

+(BOOL)windowLevelFillLookupTable:(NSArray*)lookupTable
                       startColor:(LTRasterColor*)startColor
                         endColor:(LTRasterColor*)endColor
                              low:(int)low
                             high:(int)high
                           lowBit:(unsigned int)lowBit
                          highBit:(unsigned int)highBit
                         minValue:(int)minValue
                         maxValue:(int)maxValue
                           factor:(int)factor
                            flags:(LTRasterPaletteWindowLevelFlags)flags
                            error:(NSError**)outError;

 function Leadtools.RasterPalette.WindowLevelFillLookupTable( 
   lookupTable ,
   startColor ,
   endColor ,
   low ,
   high ,
   lowBit ,
   highBit ,
   minValue ,
   maxValue ,
   factor ,
   flags 
)

public:
static void WindowLevelFillLookupTable( 
   array<RasterColor>^ lookupTable,
   RasterColor startColor,
   RasterColor endColor,
   int low,
   int high,
   int lowBit,
   int highBit,
   int minValue,
   int maxValue,
   int factor,
   RasterPaletteWindowLevelFlags flags
)

Parameters

lookupTable

Pointer to an array to be updated with the 8-bit RGB quad (i.e. lookup table).

startColor

Starting color value for the gradient.

endColor

Ending color value for the gradient.

low

The low value of the window width, in pixels.

high

The high value for the window width, in pixels.

lowBit

Value indicating the low bit used for leveling.

This is normally 0 and should be less than the highBit.

highBit

Value indicating the high bit used for leveling.

This should be greater than or equal to lowBit and less than 11 for 12-bit grayscale or 15 for 16-bit grayscale.

minValue

The image minimum value. This value can be obtained using Leadtools.ImageProcessing.Core.MinMaxValuesCommand.

maxValue

The image maximum value. This value can be obtained using Leadtools.ImageProcessing.Core.MinMaxValuesCommand.

factor

Value that indicates the factor to be applied in the method operation specified in the flags parameter.

This parameter is used only if flags is RasterPaletteWindowLevelFlags.Exponential, RasterPaletteWindowLevelFlags.Logarithmic or RasterPaletteWindowLevelFlags.Sigmoid.

If RasterPaletteWindowLevelFlags.Exponential or RasterPaletteWindowLevelFlags.Sigmoid is specified, its value can be any integer (+/-). If RasterPaletteWindowLevelFlags.Logarithmic is specified, its value should be >>= 0. If factor = 0, the lookup table will be filled linearly.

flags

Flags that indicate how the range is used to fill and the type of the lookup table and whether it contains signed or unsigned data.

Remarks

This method is available in the Medical Toolkits.

Use this method to fill in the lookup table, used in RasterImage.WindowLevel, according to the lookup table type flag.

The lookup table will be filled as follows:

Inside/Outside	MinValue-Low	Low-High	High-MaxValue
RasterPaletteWindowLevelFlags.Inside	solid black (0,0,0)	color gradient ranging from startColor to endColor	solid white (255,255,255)
RasterPaletteWindowLevelFlags.Outside	solid color (startColor)	grayscale values from solid black (0,0,0) to solid white (255, 255, 255)	solid color (endColor)
RasterPaletteWindowLevelFlags.Inside \| RasterPaletteWindowLevelFlags.DicomStyle	None	color gradient ranging from startColor to endColor	None
RasterPaletteWindowLevelFlags.Outside \| RasterPaletteWindowLevelFlags.DicomStyle	solid color (startColor)	color gradient ranging from startColor to endColor	solid color (endColor)

To fill a 16-bit lookup table use WindowLevelFillLookupTableExt.

Only TIFF and DICOM file formats are capable of saving images that have been window-leveled.

Images can be window-leveled by calling RasterImage.WindowLevel and specifying RasterWindowLevelMode.PaintAndProcessing for the flags parameter, by using the Leadtools.ImageProcessing.Core.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.

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.

Example

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

Copy Code

Imports Leadtools
  Imports Leadtools.Codecs
  Imports Leadtools.ImageProcessing
  Imports Leadtools.ImageProcessing.Core

  Public Sub WindowLevelFillLookupTableExample()
   Dim codecs As RasterCodecs = New RasterCodecs()

   codecs.ThrowExceptionsOnInvalidImages = True

   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_WindowLevel.tif")

   ' Load an image as 8 bits/pixel
   Dim image As RasterImage = codecs.Load(srcFileName, 8, CodecsLoadByteOrder.Rgb, 1, 1)

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

   ' get the lookup table size
   Dim lookupTableSize As Integer = 1 << (image.HighBit - image.LowBit + 1)

   ' get low/hight bits and minimum/maximum value of this grayscale image
   Dim minMaxBitsCmd As MinMaxBitsCommand = New MinMaxBitsCommand()
   minMaxBitsCmd.Run(image)

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

   Dim minMaxValuesCmd As MinMaxValuesCommand = New MinMaxValuesCommand()
   minMaxValuesCmd.Run(image)
   Dim minVal As Integer = minMaxValuesCmd.MinimumValue
   Dim maxVal As Integer = minMaxValuesCmd.MaximumValue

   ' create the lookup table
   Dim lookupTable As RasterColor() = New RasterColor(lookupTableSize - 1) {}

   Dim flags As RasterPaletteWindowLevelFlags = RasterPaletteWindowLevelFlags.Inside Or RasterPaletteWindowLevelFlags.Linear

   If image.Signed Then
      flags = flags Or RasterPaletteWindowLevelFlags.Signed
   End If

   ' initialize the fill lookup table parameters
   Dim startColor As RasterColor = RasterColor.FromKnownColor(RasterKnownColor.Red)
   Dim endColor As RasterColor = RasterColor.FromKnownColor(RasterKnownColor.Blue)

   Dim low As Integer = 23000
   Dim high As Integer = 45000
   Dim factor As Integer = 10

   ' fill the lookup table
   RasterPalette.WindowLevelFillLookupTable(lookupTable, startColor, endColor, low, high, lowBit, highBit, minVal, maxVal, factor, flags)

   ' now do window level on the image
   image.WindowLevel(lowBit, highBit, lookupTable, RasterWindowLevelMode.PaintAndProcessing)

   ' save it back on disk
   codecs.Save(image, destFileName, RasterImageFormat.Tif, 16)

   ' Clean up
   image.Dispose()
End Sub

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

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;

      
public void WindowLevelFillLookupTableExample()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;

   string srcFileName = Path.Combine(ImagesPath.Path, "Image1.cmp");
   string destFileName = Path.Combine(ImagesPath.Path, "Image1_WindowLevel.tif");

   // Load an image as 8 bits/pixel
   RasterImage image = codecs.Load(srcFileName, 8, CodecsLoadByteOrder.Rgb, 1, 1);

   // change the image to be 16-bit grayscale
   GrayscaleCommand grayscaleCmd = new GrayscaleCommand(16);
   grayscaleCmd.Run(image);

   // get the lookup table size
   int lookupTableSize = 1 << (image.HighBit - image.LowBit + 1);

   // get low/hight bits and minimum/maximum value of this grayscale image
   MinMaxBitsCommand minMaxBitsCmd = new MinMaxBitsCommand();
   minMaxBitsCmd.Run(image);

   int lowBit = minMaxBitsCmd.MinimumBit;
   int highBit= minMaxBitsCmd.MaximumBit;

   MinMaxValuesCommand minMaxValuesCmd = new MinMaxValuesCommand();
   minMaxValuesCmd.Run(image);
   int minVal = minMaxValuesCmd.MinimumValue;
   int maxVal = minMaxValuesCmd.MaximumValue;

   // create the lookup table
   RasterColor[] lookupTable = new RasterColor[lookupTableSize];

   RasterPaletteWindowLevelFlags flags =
      RasterPaletteWindowLevelFlags.Inside |
      RasterPaletteWindowLevelFlags.Linear;

   if(image.Signed)
      flags |= RasterPaletteWindowLevelFlags.Signed;

   // initialize the fill lookup table parameters
   RasterColor startColor= RasterColor.FromKnownColor(RasterKnownColor.Red);
   RasterColor endColor = RasterColor.FromKnownColor(RasterKnownColor.Blue);

   int low = 23000;
   int high = 45000;
   int factor = 10;

   // fill the lookup table
   RasterPalette.WindowLevelFillLookupTable(
      lookupTable,
      startColor,
      endColor,
      low,
      high,
      lowBit,
      highBit,
      minVal,
      maxVal,
      factor,
      flags);

   // now do window level on the image
   image.WindowLevel(
      lowBit,
      highBit,
      lookupTable,
      RasterWindowLevelMode.PaintAndProcessing);

   // save it back on disk
   codecs.Save(image, destFileName, RasterImageFormat.Tif, 16);

   // Clean up
   image.Dispose();
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Examples;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.Windows.Media;

public void WindowLevelFillLookupTableExample(RasterImage image, Stream destStream)
{
   // image should be 8 bits/pixel
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // change the image to be 16-bit grayscale
   GrayscaleCommand grayscaleCmd = new GrayscaleCommand(16);
   grayscaleCmd.Run(image);

   // get the lookup table size
   int lookupTableSize = 1 << (image.HighBit - image.LowBit + 1);

   // get low/hight bits and minimum/maximum value of this grayscale image
   MinMaxBitsCommand minMaxBitsCmd = new MinMaxBitsCommand();
   minMaxBitsCmd.Run(image);

   int lowBit = minMaxBitsCmd.MinimumBit;
   int highBit= minMaxBitsCmd.MaximumBit;

   MinMaxValuesCommand minMaxValuesCmd = new MinMaxValuesCommand();
   minMaxValuesCmd.Run(image);
   int minVal = minMaxValuesCmd.MinimumValue;
   int maxVal = minMaxValuesCmd.MaximumValue;

   // create the lookup table
   RasterColor[] lookupTable = new RasterColor[lookupTableSize];

   RasterPaletteWindowLevelFlags flags =
      RasterPaletteWindowLevelFlags.Inside |
      RasterPaletteWindowLevelFlags.Linear;

   if(image.Signed)
      flags |= RasterPaletteWindowLevelFlags.Signed;

   // initialize the fill lookup table parameters
   RasterColor startColor = RasterColorConverter.FromColor(Colors.Red);
   RasterColor endColor = RasterColorConverter.FromColor(Colors.Blue);

   int low = 23000;
   int high = 45000;
   int factor = 10;

   // fill the lookup table
   RasterPalette.WindowLevelFillLookupTable(
      lookupTable,
      startColor,
      endColor,
      low,
      high,
      lowBit,
      highBit,
      minVal,
      maxVal,
      factor,
      flags);

   // now do window level on the image
   image.WindowLevel(
      lowBit,
      highBit,
      lookupTable,
      RasterWindowLevelMode.PaintAndProcessing);

   // save it back on disk
   codecs.Save(image, destStream, RasterImageFormat.Tif, 16);

   // Clean up
   image.Dispose();
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.Windows.Media

Public Sub WindowLevelFillLookupTableExample(ByVal image As RasterImage, ByVal destStream As Stream)
   ' image should be 8 bits/pixel
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True
   ' change the image to be 16-bit grayscale
   Dim grayscaleCmd As GrayscaleCommand = New GrayscaleCommand(16)
   grayscaleCmd.Run(image)

   ' get the lookup table size
   Dim lookupTableSize As Integer = 1 << (image.HighBit - image.LowBit + 1)

   ' get low/hight bits and minimum/maximum value of this grayscale image
   Dim minMaxBitsCmd As MinMaxBitsCommand = New MinMaxBitsCommand()
   minMaxBitsCmd.Run(image)

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

   Dim minMaxValuesCmd As MinMaxValuesCommand = New MinMaxValuesCommand()
   minMaxValuesCmd.Run(image)
   Dim minVal As Integer = minMaxValuesCmd.MinimumValue
   Dim maxVal As Integer = minMaxValuesCmd.MaximumValue

   ' create the lookup table
   Dim lookupTable As RasterColor() = New RasterColor(lookupTableSize - 1){}

   Dim flags As RasterPaletteWindowLevelFlags = RasterPaletteWindowLevelFlags.Inside Or RasterPaletteWindowLevelFlags.Linear

   If image.Signed Then
      flags = flags Or RasterPaletteWindowLevelFlags.Signed
   End If

   ' initialize the fill lookup table parameters
   Dim startColor As RasterColor = RasterColorConverter.FromColor(Colors.Red)
   Dim endColor As RasterColor = RasterColorConverter.FromColor(Colors.Blue)

   Dim low As Integer = 23000
   Dim high As Integer = 45000
   Dim factor As Integer = 10

   ' fill the lookup table
   RasterPalette.WindowLevelFillLookupTable(lookupTable, startColor, endColor, low, high, lowBit, highBit, minVal, maxVal, factor, flags)

   ' now do window level on the image
   image.WindowLevel(lowBit, highBit, lookupTable, RasterWindowLevelMode.PaintAndProcessing)

   ' save it back on disk
   codecs.Save(image, destStream, RasterImageFormat.Tif, 16)

   ' Clean up
   image.Dispose()
End Sub

Requirements

Target Platforms

Reference

RasterPalette Class
RasterPalette Members