SetLookupTable Method

Sets the 8-bit lookup table (LUT) of this RasterImage.

Syntax

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

public void SetLookupTable( 
   RasterColor[] value
)

'Declaration
 
Public Sub SetLookupTable( _
   ByVal value() As RasterColor _
)

'Usage
 
Dim instance As RasterImage
Dim value() As RasterColor
 
instance.SetLookupTable(value)

public void SetLookupTable( 
   RasterColor[] value
)

 function Leadtools.RasterImage.SetLookupTable( 
   value 
)

public:
void SetLookupTable( 
   array<RasterColor>^ value
)

Parameters

value: An array of RasterColor structures which represent the lookup table (LUT) of this RasterImage.

Remarks

The lookup table (LUT) is used when the value of UseLookupTable is set to true.

The 8-bit and 16-bit lookup tables are synchronized, so when you change one, the other is changed as well The 16-bit lookup table (SetLookupTable16) has more precision so it is recommended you use the 16-bit LUT instead of the 8-bit LUT.

LUT is only used for 10-16 bit extended grayscale image or 10-16 bit palette color image. To update the palette in 1-8 bit image use SetPalette. For more information, refer to Grayscale Images.

LUT is also used for displaying extended Palette color image such as bit stored is 16-bit and LUT contains color value. This is typical of Ultra Sound image.

Example

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

Private Sub SetLookupTable()
   DicomEngine.Startup()

   ' Get the path of the LEADTOOLS images directory
   Dim strImagesDirectory As String = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) & "//LEADTOOLS Images//"

   ' Create a RasterCodecs class for saving out images
   Dim codecs As RasterCodecs = New RasterCodecs()

   ' Load a dataset
   Dim ds As DicomDataSet = New DicomDataSet()
   ds.Load(strImagesDirectory & "IMAGE3.dcm", DicomDataSetLoadFlags.None)

   ' Get the image but do NOT auto-apply any of the LUTs
   Dim element As DicomElement = ds.FindFirstElement(Nothing, DicomTag.PixelData, True)
   Dim image As RasterImage = ds.GetImage(element, 0, 16, RasterByteOrder.Gray, DicomGetImageFlags.None)
   image.UseLookupTable = True

   ' Save out the image without any LUTs applied.  It should be black
   codecs.Save(image, strImagesDirectory & "BeforeSetLookupTable.bmp", RasterImageFormat.Bmp, 8)

   ' Create a LUT
   Dim lut As RasterColor() = New RasterColor(CInt(Math.Pow(2, 16)) - 1) {}

   ' Get the Minimum and Maximum values so we can calculate appropriate LUT values.
   Dim cmdMinMax As MinMaxValuesCommand = New MinMaxValuesCommand()
   cmdMinMax.Run(image)
   Dim maxVal As Integer = cmdMinMax.MaximumValue
   Dim minVal As Integer = cmdMinMax.MinimumValue

   Dim i As Integer = 0
   Do While i < lut.Length
      lut(i).R = Convert.ToByte(Math.Min(255, ((i - minVal) * 255 / (maxVal - minVal))))
      lut(i).G = lut(i).R
      lut(i).B = lut(i).R
      i += 1
   Loop

   ' Set the new lookup table
   image.SetLookupTable(lut)

   ' Save out the image with the LUT applied.  It should look normal
   codecs.Save(image, strImagesDirectory & "AfterSetLookupTable.bmp", RasterImageFormat.Bmp, 8)

   DicomEngine.Shutdown()
End Sub

public void SetLookupTable()
   {
      DicomEngine.Startup();

      // Create a RasterCodecs class for saving out images
      RasterCodecs codecs = new RasterCodecs();

      // Load a dataset
      DicomDataSet ds = new DicomDataSet();
      ds.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE3.dcm"), DicomDataSetLoadFlags.None);

      // Get the image but do NOT auto-apply any of the LUTs
      DicomElement element = ds.FindFirstElement(null, DicomTag.PixelData, true);
      RasterImage image = ds.GetImage(element, 0, 16, RasterByteOrder.Gray, DicomGetImageFlags.None);
      image.UseLookupTable = true;

      // Save out the image without any LUTs applied.  It should be black
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "BeforeSetLookupTable.bmp"), RasterImageFormat.Bmp, 8);

      // Create a LUT
      RasterColor[] lut = new RasterColor[(int)Math.Pow(2, 16)];

      // Get the Minimum and Maximum values so we can calculate appropriate LUT values.
      MinMaxValuesCommand cmdMinMax = new MinMaxValuesCommand();
      cmdMinMax.Run(image);
      int maxVal = cmdMinMax.MaximumValue;
      int minVal = cmdMinMax.MinimumValue;

      for(int i = 0; i < lut.Length; i++)
      {
         lut[i].R = Convert.ToByte(Math.Min(255, ((i - minVal) * 255 / (maxVal - minVal))));
         lut[i].G = lut[i].R;
         lut[i].B = lut[i].R;
      }

      // Set the new lookup table
      image.SetLookupTable(lut);

      // Save out the image with the LUT applied.  It should look normal
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "AfterSetLookupTable.bmp"), RasterImageFormat.Bmp, 8);

      DicomEngine.Shutdown();
   }

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

RasterImageExamples.prototype.SetLookupTable = function ( ) 
{
   Tools.SetLicense ( ) ;

   with (Leadtools) {
      with (Leadtools.Codecs) {
         with (Leadtools.Dicom) {
            DicomEngine.startup();

            // Create a RasterCodecs class for saving out images
            var codecs = new RasterCodecs();
            var image;
            // Load a dataset
            var ds = new DicomDataSet();
            var srcFileName = "Assets\\IMAGE3.dcm";
            return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
               return ds.loadAsync(LeadStreamFactory.create(loadFile), DicomDataSetLoadFlags.none)})
                  .then(function () {

                     // Get the image but do NOT auto-apply any of the LUTs
                     var element = ds.findFirstElement(null, Leadtools.Dicom.Constants.DicomTagConstants.pixel_DATA, true);
                     image = ds.getImage(element, 0, 16, DicomGetImageFlags.none);
                     image.useLookupTable = true;

                     // Save out the image without any LUTs applied.  It should be black
                     return Tools.AppLocalFolder().createFileAsync("BeforeSetLookupTable.bmp")
                  })
                  .then(function (saveFile) {
                     var saveStream = LeadStreamFactory.create(saveFile);
                     return codecs.saveAsync(image, saveStream, RasterImageFormat.bmp, 8)
                  })
                  .then(function () {

                     // Create a LUT
                     var lut = new Array(Math.pow(2, 16));

                     // Get the Minimum and Maximum values so we can calculate appropriate LUT values.
                     var cmdMinMax = new Leadtools.ImageProcessing.Core.MinMaxValuesCommand();
                     cmdMinMax.run(image);
                     var maxVal = cmdMinMax.maximumValue;
                     var minVal = cmdMinMax.minimumValue;

                     for (var i = 0; i < lut.length; i++) {
                        var color = {};

                        color.a = 255;
                        color.reserved = 0;
                        color.r = Math.max(0, (Math.min(255, ((i - minVal) * 255 / (maxVal - minVal)))));
                        color.g = color.r;
                        color.b = color.r;
                        lut[i] = color;
                     }

                     // Set the new lookup table
                     image.setLookupTable(lut);

                     // Save out the image with the LUT applied.  It should look normal
                     return Tools.AppLocalFolder().createFileAsync("AfterSetLookupTable.bmp")
                  })
                  .then(function (saveFile) {
                     saveStream = LeadStreamFactory.create(saveFile);
                     return codecs.saveAsync(image, saveStream, RasterImageFormat.bmp, 0)
                  })
                  .then(function () {

                     DicomEngine.shutdown();
                  });
         }
      }
   }
}

[TestMethod]
public async Task SetLookupTable()
{
   DicomEngine.Startup();
   // Create a RasterCodecs class for saving out images
   RasterCodecs codecs = new RasterCodecs();

   // Load a dataset
   DicomDataSet ds = new DicomDataSet();
   string srcFileName = @"Assets\IMAGE3.dcm";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   await ds.LoadAsync(LeadStreamFactory.Create(loadFile), DicomDataSetLoadFlags.None);

   // Get the image but do NOT auto-apply any of the LUTs
   DicomElement element = ds.FindFirstElement(null, Leadtools.Dicom.Constants.DicomTagConstants.PixelData, true);
   RasterImage image = ds.GetImage(element, 0, 16, DicomGetImageFlags.None);
   image.UseLookupTable = true;

   // Save out the image without any LUTs applied.  It should be black
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync("BeforeSetLookupTable.bmp");
   ILeadStream saveStream = LeadStreamFactory.Create(saveFile);
   await codecs.SaveAsync(image, saveStream, RasterImageFormat.Bmp, 8);

   // Create a LUT
   RasterColor[] lut = new RasterColor[(int)Math.Pow(2, 16)];

   // Get the Minimum and Maximum values so we can calculate appropriate LUT values.
   MinMaxValuesCommand cmdMinMax = new MinMaxValuesCommand();
   cmdMinMax.Run(image);
   int maxVal = cmdMinMax.MaximumValue;
   int minVal = cmdMinMax.MinimumValue;

   for (int i = 0; i < lut.Length; i++)
   {
      lut[i].R = Convert.ToByte(Math.Min(255, ((i - minVal) * 255 / (maxVal - minVal))));
      lut[i].G = lut[i].R;
      lut[i].B = lut[i].R;
   }

   // Set the new lookup table
   image.SetLookupTable(lut);

   // Save out the image with the LUT applied.  It should look normal
   saveFile = await Tools.AppLocalFolder.CreateFileAsync("AfterSetLookupTable.bmp");
   saveStream = LeadStreamFactory.Create(saveFile);
   await codecs.SaveAsync(image, saveStream, RasterImageFormat.Bmp, 0);

   DicomEngine.Shutdown();
}

public void SetLookupTable(Stream dataSetStream, Stream destStream1, Stream destStream2)
{
   // Create a RasterCodecs class for saving out images
   RasterCodecs codecs = new RasterCodecs();
   // Load a dataset
   DicomDataSet ds = new DicomDataSet();
   ds.Load(dataSetStream, DicomDataSetLoadFlags.None);

   // Get the image but do NOT auto-apply any of the LUTs
   DicomElement element = ds.FindFirstElement(null, DicomTag.PixelData, true);
   RasterImage image = ds.GetImage(element, 0, 16, RasterByteOrder.Gray, DicomGetImageFlags.None);
   image.UseLookupTable = true;

   // Save out the image without any LUTs applied.  It should be black
   codecs.Save(image, destStream1, RasterImageFormat.Bmp, 8);

   // Create a LUT
   RasterColor[] lut = new RasterColor[(int)Math.Pow(2, 16)];

   // Get the Minimum and Maximum values so we can calculate appropriate LUT values.
   MinMaxValuesCommand cmdMinMax = new MinMaxValuesCommand();
   cmdMinMax.Run(image);
   int maxVal = cmdMinMax.MaximumValue;
   int minVal = cmdMinMax.MinimumValue;

   for (int i = 0; i < lut.Length; i++)
   {
      lut[i].R = Convert.ToByte(Math.Min(255, ((i - minVal) * 255 / (maxVal - minVal))));
      lut[i].G = lut[i].R;
      lut[i].B = lut[i].R;
   }

   // Set the new lookup table
   image.SetLookupTable(lut);

   // Save out the image with the LUT applied.  It should look normal
   codecs.Save(image, destStream2, RasterImageFormat.Bmp, 8);

   DicomEngine.Shutdown();
}

Public Sub SetLookupTable(ByVal dataSetStream As Stream, ByVal destStream1 As Stream, ByVal destStream2 As Stream)
   ' Create a RasterCodecs class for saving out images
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Load a dataset
   Dim ds As DicomDataSet = New DicomDataSet()
   ds.Load(dataSetStream, DicomDataSetLoadFlags.None)

   ' Get the image but do NOT auto-apply any of the LUTs
   Dim element As DicomElement = ds.FindFirstElement(Nothing, DicomTag.PixelData, True)
   Dim image As RasterImage = ds.GetImage(element, 0, 16, RasterByteOrder.Gray, DicomGetImageFlags.None)
   image.UseLookupTable = True

   ' Save out the image without any LUTs applied.  It should be black
   codecs.Save(image, destStream1, RasterImageFormat.Bmp, 8)

   ' Create a LUT
   Dim lut As RasterColor() = New RasterColor(CInt(Math.Pow(2, 16)) - 1){}

   ' Get the Minimum and Maximum values so we can calculate appropriate LUT values.
   Dim cmdMinMax As MinMaxValuesCommand = New MinMaxValuesCommand()
   cmdMinMax.Run(image)
   Dim maxVal As Integer = cmdMinMax.MaximumValue
   Dim minVal As Integer = cmdMinMax.MinimumValue

   Dim i As Integer = 0
   Do While i < lut.Length
      lut(i).R = Convert.ToByte(Math.Min(255, ((i - minVal) * 255 / (maxVal - minVal))))
      lut(i).G = lut(i).R
      lut(i).B = lut(i).R
      i += 1
   Loop

   ' Set the new lookup table
   image.SetLookupTable(lut)

   ' Save out the image with the LUT applied.  It should look normal
   codecs.Save(image, destStream2, RasterImageFormat.Bmp, 8)

   DicomEngine.Shutdown()
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

RasterImage Class
RasterImage Members
Leadtools.Drawing.RasterPaintCallbacks
Implementing custom paint