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GetUserLookupTable Method


Updates the lookup table, based on a curve that passes through the specified points.

public static int GetUserLookupTable( 
   int[] lookupTable, 
   LeadPoint[] userPoints 
Public Shared Function GetUserLookupTable( _ 
   ByVal lookupTable() As Integer, _ 
   ByVal userPoints() As LeadPoint _ 
) As Integer 
+ (NSUInteger)getUserLookupTable:(unsigned int *)lookupTable 
                      userPoints:(const LeadPoint *)userPoints 
                           error:(NSError **)error 
public static int getUserLookupTable( 
   int[] lookupTable,  
   LeadPoint[] userPoints 
static int GetUserLookupTable(  
   array<int>^ lookupTable, 
   array<LeadPoint>^ userPoints 


Lookup table array to be filled by this method.

Array of LeadPoint structures that contain the points on the curve used to update the lookup table.

Return Value

return the number of entries in the lookup table array that were actually updated by this method.

  • This method will update the lookup table array using the best curve that passes through the points specified in the userPoint array. The points in the array do not need to be sorted. In most cases, this method is used with the RemapIntensityCommand method.
  • The length of the lookup table array depends upon the number of bits being used, as follows:

    Value Meaning
    65536 16-bit / sample image
    4096 12-bit / sample image
    256 256 8-bit / sample image


This example will brighten the loaded bitmap using the lookup table updated by the GetUserLookupTable method.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Effects; 
using Leadtools.ImageProcessing.Color; 
public void GetUserLookupTableExample() 
   // 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[] LookupTable = new int[256]; 
   LeadPoint[] UserPoint = new LeadPoint[3]; 
   UserPoint[0] = new LeadPoint(0, 0); 
   UserPoint[1] = new LeadPoint(128, 150); 
   UserPoint[2] = new LeadPoint(255, 255); 
   //Get Lookup table where the array effected by user data method. 
   EffectsUtilities.GetUserLookupTable(LookupTable, UserPoint); 
   RemapIntensityCommand command = new RemapIntensityCommand(); 
   command.Flags = RemapIntensityCommandFlags.Master; 
   command.LookupTable = LookupTable; 
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.ImageProcessing.Effects 
Public Sub GetUserLookupTableExample() 
   Dim codecs As New RasterCodecs() 
   codecs.ThrowExceptionsOnInvalidImages = True 
   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg")) 
   ' Prepare the command 
   Dim LookupTable() As Integer 
   ReDim LookupTable(255) 
   Dim UserPoint() As LeadPoint 
   ReDim UserPoint(2) 
   UserPoint(0) = New LeadPoint(0, 0) 
   UserPoint(1) = New LeadPoint(128, 150) 
   UserPoint(2) = New LeadPoint(255, 255) 
   'Get Lookup table where the array effected by user data method. 
   EffectsUtilities.GetUserLookupTable(LookupTable, UserPoint) 
   Dim command As RemapIntensityCommand = New RemapIntensityCommand 
   command.Flags = RemapIntensityCommandFlags.Master 
   command.LookupTable = LookupTable 
   codecs.Save(leadImage, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24) 
End Sub 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class 


Target Platforms

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Leadtools.ImageProcessing.Effects Assembly