GetUserLookupTable Method

Summary

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

Syntax

Objective-C

C++/CLI

Java

Python

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

+ (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 
)

def GetUserLookupTable(self,lookupTable,] 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.

Java

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:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.IOException; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.imageprocessing.color.*; 
import leadtools.imageprocessing.effects.*; 
 
 
public void getUserLookupTableExample() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.setThrowExceptionsOnInvalidImages(true); 
 
   RasterImage image = codecs.load(combine(LEAD_VARS_IMAGES_DIR, "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.setFlags(RemapIntensityCommandFlags.MASTER.getValue()); 
   command.setLookupTable(lookupTable); 
   int change = command.run(image); 
   assertTrue(change != RasterImageChangedFlags.NONE); 
 
   codecs.save(image, combine(LEAD_VARS_IMAGES_DIR, "Result.jpg"), RasterImageFormat.JPEG, 24); 
   System.out.println("Command run, and image saved to " + combine(LEAD_VARS_IMAGES_DIR, "Result.jpg")); 
}