GetUserLookupTable Method

Summary

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

Syntax

Objective-C

C++

Java

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 
               lookupTableLength:(NSUInteger)lookupTableLength 
                      userPoints:(const LeadPoint *)userPoints 
                 userPointsCount:(NSUInteger)userPointsCount 
                           error:(NSError **)error

public static int getUserLookupTable( 
   int[] lookupTable,  
   LeadPoint[] userPoints 
)

public: 
static int GetUserLookupTable(  
   array<int>^ lookupTable, 
   array<LeadPoint>^ userPoints 
)

Parameters

lookupTable
Lookup table array to be filled by this method.

userPoints
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.

Remarks

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

Example

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; 
   command.Run(image); 
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24); 
 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\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 
   command.Run(leadImage) 
   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:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

EffectsUtilities Class

EffectsUtilities Members

Leadtools.ImageProcessing.Color.RemapIntensityCommand

Leadtools.ImageProcessing.Color.AdjustTintCommand

Leadtools.ImageProcessing.Color.GammaCorrectExtendedCommand

Download our FREE evaluation

Help Version 21.0.2021.7.2

Leadtools.ImageProcessing.Effects Assembly

Introduction

Getting Started

Namespaces

Leadtools.ImageProcessing.Effects Namespace

Assemblies