LEADTOOLS Image Processing (Leadtools.ImageProcessing.Color assembly) Send comments on this topic. | Back to Introduction - All Topics | Help Version 17.0.3.29
RemapHueCommand Class
See Also  Members  



Uses a lookup table to change an image's hue values. The saturation and value tables change S and V values only if a particular hue value is marked as non-zero in the Mask property. It is used for all resolutions, including 48 and 64-bit images. Supported in Silverlight, Windows Phone 7

Object Model

RemapHueCommand Class

Syntax

Visual Basic (Declaration) 
Public Class RemapHueCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As RemapHueCommand
C# 
public class RemapHueCommand : Leadtools.ImageProcessing.RasterCommand, IRasterCommand 
C++/CLI 
public ref class RemapHueCommand : public Leadtools.ImageProcessing.RasterCommand, IRasterCommand 

Example

Run the RemapHueCommand on an image and change all green hues (and hues near green).

Visual BasicCopy Code
Public Function INCREMENT_S1(ByVal x As Integer, ByVal Length As Integer) As Integer
   Return ((x + 1) Mod Length)
End Function
Public Function DECREMENT_S1(ByVal x As Integer, ByVal Length As Integer) As Integer
   Return ((x + (Length - 1)) Mod Length)
End Function

Public Function ADD_S1(ByVal x As Integer, ByVal y As Integer, ByVal Length As Integer) As Integer
   Return ((x + y) Mod Length)
End Function


Public Sub RemapHueCommandCommandExample()
   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 MaskTable() As Integer
   Dim HueTable() As Integer
   Dim hsvRef As RasterHsvColor
   Dim HueGreen As Integer
   Dim HueChange As Integer

   Dim Change As Integer
   Dim i As Integer
   Dim Count As Integer
   Dim Length As Integer

   If (leadImage.BitsPerPixel >= 48) Then

      Length = 65536

   ElseIf (Not (leadImage.BitsPerPixel = 16 Or leadImage.BitsPerPixel = 12)) Then
      Length = 256
   ElseIf (IsNothing(leadImage.GetLookupTable) And leadImage.UseLookupTable) Then
      Length = 256
   Else
      Length = (1 << leadImage.BitsPerPixel)
   End If
   'Allocate tables
   ReDim MaskTable(Length - 1)
   ReDim HueTable(Length - 1)

   'Initialize tables
   For i = 0 To Length - 1
      MaskTable(i) = 0
      HueTable(i) = i
   Next

   'Get the hue for green
   hsvRef = RasterHsvColor.FromRasterColor(New RasterColor(0, 255, 0))

   HueGreen = hsvRef.H

   'Obtain new hue  
   hsvRef = RasterHsvColor.FromRasterColor(New RasterColor(255, 128, 0))
   Change = hsvRef.H - HueGreen
   If (Change > 0) Then
      HueChange = Change
   Else
      HueChange = Change + Length - 1
   End If

   HueGreen = (HueGreen * (Length - 1)) \ 255
   HueChange = (HueChange * (Length - 1)) \ 255

   'Set values in HueTable, MaskTable 
   HueTable(HueGreen) = HueTable(HueGreen) + HueChange
   MaskTable(HueGreen) = 1

   'set the hues near green (+/- 15)
   i = INCREMENT_S1(HueGreen, Length)

   For Count = (15 * (Length - 1)) \ 255 To 1 Step -1
      i = INCREMENT_S1(i, Length)
      HueTable(i) = ADD_S1(HueTable(i), HueChange, Length)
      MaskTable(i) = 1
   Next

   i = DECREMENT_S1(HueGreen, Length)

   For Count = (15 * (Length - 1)) \ 255 To 1 Step -1

      i = DECREMENT_S1(i, Length)
      HueTable(i) = ADD_S1(HueTable(i), HueChange, Length)
      MaskTable(i) = 1
   Next
   Dim command As RemapHueCommand = New RemapHueCommand(MaskTable, HueTable, Nothing, Nothing, Length)

   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:\Users\Public\Documents\LEADTOOLS Images"
End Class
C#Copy Code
public int INCREMENT_S1(int x, int Length)
   {
      return ((x + 1) % Length);
   }
   public int DECREMENT_S1(int x, int Length)
   {
      return ((x + (Length - 1)) % Length);
   }

   public int ADD_S1(int x, int y, int Length)
   {
      return ((x + y) % Length);
   }


   public void RemapHueCommandCommandExample()
   {
      // 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[]  MaskTable;
      int[]  HueTable;
      RasterHsvColor hsvRef;
      int    HueGreen, HueChange;
      int    Change;
      int    i, Count;
      int    Length;

      if(image.BitsPerPixel >= 48)
         Length = 0x10000;
      else if(!(image.BitsPerPixel == 16 || image.BitsPerPixel == 12))
         Length = 256;
      else if(image.GetLookupTable() != null && image.UseLookupTable)
         Length = 256;
      else
         Length = (1 << image.BitsPerPixel);

      //Allocate tables
      MaskTable = new int[Length];
      HueTable  = new int[Length];

      //Initialize tables
      for (i = 0; i < Length; i++)
      {
         MaskTable[i] = 0;
         HueTable[i] = i;
      }

      //Get the hue for green
      hsvRef = RasterHsvColor.FromRasterColor(new RasterColor(0,255,0));

      HueGreen = hsvRef.H;

      //Obtain new hue  
      hsvRef =  RasterHsvColor.FromRasterColor(new RasterColor(255, 128, 0));
      Change = (int)hsvRef.H - (int)HueGreen;
      HueChange = (Change>0) ? (int)Change : (int)(Change + Length - 1);
      HueGreen   *= (Length - 1)/255;
      HueChange *= (Length - 1)/255;

      //Set values in HueTable, MaskTable 
      HueTable[HueGreen] = (HueTable[HueGreen] + HueChange);
      MaskTable[HueGreen] = 1;

      //set the hues near green (+/- 15)
      Count = (15 * (Length - 1))/255;
      for (i = INCREMENT_S1(HueGreen, Length); Count > 0; i = INCREMENT_S1(i, Length), Count--)
      {
         HueTable[i] = ADD_S1(HueTable[i], HueChange, Length);
         MaskTable[i] = 1;
      }

      Count = (15 * (Length - 1))/255;
      for (i = DECREMENT_S1(HueGreen, Length); Count > 0; i = DECREMENT_S1(i, Length), Count--)
      {
         HueTable[i] = ADD_S1(HueTable[i], HueChange, Length);
         MaskTable[i] = 1;
      }

      RemapHueCommand command = new RemapHueCommand(MaskTable, HueTable, null, null, Length);
      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:\Users\Public\Documents\LEADTOOLS Images";
}
SilverlightCSharpCopy Code
public int INCREMENT_S1(int x, int Length)
{
   return ((x + 1) % Length);
}
public int DECREMENT_S1(int x, int Length)
{
   return ((x + (Length - 1)) % Length);
}

public int ADD_S1(int x, int y, int Length)
{
   return ((x + y) % Length);
}

public void RemapHueCommandCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   int[]  MaskTable;
   int[]  HueTable;
   RasterHsvColor hsvRef;
   int    HueGreen, HueChange;
   int    Change;
   int    i, Count;
   int    Length;

   if(image.BitsPerPixel >= 48)
      Length = 0x10000;
   else if(!(image.BitsPerPixel == 16 || image.BitsPerPixel == 12))
      Length = 256;
   else if(image.GetLookupTable() != null && image.UseLookupTable)
      Length = 256;
   else
      Length = (1 << image.BitsPerPixel);

   //Allocate tables
   MaskTable = new int[Length];
   HueTable  = new int[Length];

   //Initialize tables
   for (i = 0; i < Length; i++)
   {
      MaskTable[i] = 0;
      HueTable[i] = i;
   }

   //Get the hue for green
   hsvRef = RasterHsvColor.FromRasterColor(new RasterColor(0,255,0));

   HueGreen = hsvRef.H;

   //Obtain new hue  
   hsvRef =  RasterHsvColor.FromRasterColor(new RasterColor(255, 128, 0));
   Change = hsvRef.H - HueGreen;
   HueChange = (Change>0) ? Change : (Change + Length - 1);
   HueGreen   *= (Length - 1)/255;
   HueChange *= (Length - 1)/255;

   //Set values in HueTable, MaskTable 
   HueTable[HueGreen] = (HueTable[HueGreen] + HueChange);
   MaskTable[HueGreen] = 1;

   //set the hues near green (+/- 15)
   Count = (15 * (Length - 1))/255;
   for (i = INCREMENT_S1(HueGreen, Length); Count > 0; i = INCREMENT_S1(i, Length), Count--)
   {
      HueTable[i] = ADD_S1((int)HueTable[i], HueChange, Length);
      MaskTable[i] = 1;
   }

   Count = (15 * (Length - 1))/255;
   for (i = DECREMENT_S1(HueGreen, Length); Count > 0; i = DECREMENT_S1(i, Length), Count--)
   {
      HueTable[i] = ADD_S1(HueTable[i], HueChange, Length);
      MaskTable[i] = 1;
   }

   RemapHueCommand command = new RemapHueCommand(MaskTable, HueTable, null, null, Length);
   command.Run(image);

   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}
SilverlightVBCopy Code
Public Function INCREMENT_S1(ByVal x As Integer, ByVal Length As Integer) As Integer
   Return ((x + 1) Mod Length)
End Function
Public Function DECREMENT_S1(ByVal x As Integer, ByVal Length As Integer) As Integer
   Return ((x + (Length - 1)) Mod Length)
End Function

Public Function ADD_S1(ByVal x As Integer, ByVal y As Integer, ByVal Length As Integer) As Integer
   Return ((x + y) Mod Length)
End Function

Public Sub RemapHueCommandCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim MaskTable As Integer()
   Dim HueTable As Integer()
   Dim hsvRef As RasterHsvColor
   Dim HueGreen, HueChange As Integer
   Dim Change As Integer
   Dim i, Count As Integer
   Dim Length As Integer

   If image.BitsPerPixel >= 48 Then
      Length = &H10000
   Else If Not(image.BitsPerPixel = 16 OrElse image.BitsPerPixel = 12) Then
      Length = 256
   Else If Not image.GetLookupTable() Is Nothing AndAlso image.UseLookupTable Then
      Length = 256
   Else
      Length = (1 << image.BitsPerPixel)
   End If

   'Allocate tables
   MaskTable = New Integer(Length - 1){}
   HueTable = New Integer(Length - 1){}

   'Initialize tables
   i = 0
   Do While i < Length
      MaskTable(i) = 0
      HueTable(i) = i
      i += 1
   Loop

   'Get the hue for green
   hsvRef = RasterHsvColor.FromRasterColor(New RasterColor(0,255,0))

   HueGreen = hsvRef.H

   'Obtain new hue  
   hsvRef = RasterHsvColor.FromRasterColor(New RasterColor(255, 128, 0))
   Change = hsvRef.H - HueGreen
   If (Change>0) Then
      HueChange = Change
   Else
      HueChange = (Change + Length - 1)
   End If
   HueGreen *= (Length - 1)/255
   HueChange *= (Length - 1)/255

   'Set values in HueTable, MaskTable 
   HueTable(HueGreen) = (HueTable(HueGreen) + HueChange)
   MaskTable(HueGreen) = 1

   'set the hues near green (+/- 15)
   Count = (15 * (Length - 1))/255
   i = INCREMENT_S1(HueGreen, Length)
   Do While Count > 0
      HueTable(i) = ADD_S1(CInt(HueTable(i)), HueChange, Length)
      MaskTable(i) = 1
      i = INCREMENT_S1(i, Length)
      Count -= 1
   Loop

   Count = (15 * (Length - 1))/255
   i = DECREMENT_S1(HueGreen, Length)
   Do While Count > 0
      HueTable(i) = ADD_S1(HueTable(i), HueChange, Length)
      MaskTable(i) = 1
      i = DECREMENT_S1(i, Length)
      Count -= 1
   Loop

   Dim command As RemapHueCommand = New RemapHueCommand(MaskTable, HueTable, Nothing, Nothing, Length)
   command.Run(image)

   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   image.Dispose()
End Sub

Remarks

  • This command can be used to change a range of colors to another range of colors. For example, it could be used to change all red pixels to any color, where a red pixel can have any brightness (V) and any amount of white (saturation). A red pixel in this case would be RGB(x,y,y) where 0 <= x <(LookUpTableLength - 1) and 0 <= y < x or in the HSV color space HSV(0,x,x) where 0<=x<=(LookUpTableLength - 1)
  • The Mask lookup table identifies which values in the HueTable are valid. If a Mask value is 0, then the corresponding value in the HueTable is ignored. If a Mask value is non-zero, then the corresponding value in the HueTable is used. For example, if a pixel has a hue value of 240 and Mask[240] is nonzero, then the hue value of 240 is replaced with HueTable[240]. Traditionally, hue ranges from 0 to 359. For the lookup table, the range of 0 to 359 is remapped to a range of 0.. LookUpTableLength - 1. For example, if LookUpTableLength = 256
  • This command supports 48 and 64-bit colored images.
  • This command does not support signed data images.
  • This command does not support 32-bit grayscale images.
For more information, refer to Changing Brightness and Contrast.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Color.RemapHueCommand

Requirements

Target Platforms: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)

See Also