The LEAD Color Conversion toolkit provides emulation tables as one of its conversion methods. This method however is provided only for the following conversions:

• CMYK to RGB.
• CIELab to RGB.
• RGB to CIELab.

The Emulation tables' method supports both built-in and custom options. For built-in emulation tables, use the ConversionMethodFlags.UseEmulationTables option. The custom emulation tables' option, ConversionMethodFlags.UseCustomEmulationTables, provides custom conversion using user-supplied images, converted from the source images distributed with the library, by any tool, as follows:

Conversion	Source	Convert to
CMYK to RGB	src_cmyk_image.tif	RGB image (i.e. dst_cmyk2rgb_image.tif)
RGB to Lab	src_rgb_image.tif	Lab image (i.e. dst_rgb2lab_image.tif)
Lab to RGB	src_lab_image.tif	RGB image (i.e. dst_lab2rgb_image.tif)

A set of images, already converted and ready for use (dst_cmyk2rgb_image.tif, dst_rgb2lab_image.tif, and dst_lab2rgb_image.tif), is provided. However, using the provided set of converted images will produce the same results as the built-in emulation tables.

• The code below shows how a conversion can be done using the built-in tables:

[Visual Basic]

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ColorConversion

Private Function BuiltInTablesConvertCmykToRgb(ByVal cmykBuffer As Byte(), ByVal width As Integer, ByVal height As Integer) As Byte()
  ' StartUp the ColorConversion.
  RasterColorConverter.Startup()

  ' Initialize the Rgb buffer array
  Dim rgbBuffer As Byte() = New Byte(cmykBuffer.Length - 1){}

  ' Initialize a new ConversionParameters class object.
  Dim convParams As ConversionParameters = New ConversionParameters()

  ' Conversion with options.
  ' The conversion will be done with the options specified in the
  ' convParams variable

  ' We want to use built-in emulation tables 
  convParams.Method = ConversionMethodFlags.UseEmulationTables

  ' Set the quantization to 8
  convParams.Quantization = 8

  ' set the active conversion method 
  convParams.ActiveMethod = ConversionMethodFlags.UseEmulationTables

  ' Initialize a new Converter object
  Dim converter As RasterColorConverter = New RasterColorConverter()

  Try
    ' Initialize the color conversion 
    converter.Start(ConversionColorFormat.Cmyk, ConversionColorFormat.Rgb, convParams)

    ' Convert the image buffer 
    converter.Convert(cmykBuffer, 0, rgbBuffer, 0, width, height, 0, 0)

    ' Stop the conversion 
    converter.Stop()
  Catch ex As Exception
    MessageBox.Show(ex.Message)
    rgbBuffer = Nothing
  End Try

  ' Shutdown the ColorConversion.
  RasterColorConverter.Shutdown()

  ' return the converted buffer.
  Return rgbBuffer
End Function

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ColorConversion;

private byte[] BuiltInTablesConvertCmykToRgb(byte[] cmykBuffer, int width, int height)
{
   // StartUp the ColorConversion.
   RasterColorConverter.Startup();

   // Initialize the Rgb buffer array
   byte[] rgbBuffer = new byte[cmykBuffer.Length];

   // Initialize a new ConversionParameters class object.
   ConversionParameters convParams = new ConversionParameters();

   // Conversion with options.
   // The conversion will be done with the options specified in the
   // convParams variable

   // We want to use built-in emulation tables 
   convParams.Method = ConversionMethodFlags.UseEmulationTables;

   // set the active conversion method 
   convParams.ActiveMethod = ConversionMethodFlags.UseEmulationTables;

   // set the quantization to 8
   convParams.Quantization = 8;

   // Initialize a new Converter object
   RasterColorConverter converter = new RasterColorConverter();

   try
   {
      // Initialize the color conversion 
      converter.Start(ConversionColorFormat.Cmyk,
          ConversionColorFormat.Rgb,
          convParams);

      // Convert the image buffer 
      converter.Convert(cmykBuffer, 0, rgbBuffer, 0, width, height, 0, 0);

      // Stop the conversion 
      converter.Stop();
   }
   catch (Exception ex)
   {
      MessageBox.Show(ex.Message);
      rgbBuffer = null;
   }

   // Shutdown the ColorConversion.
   RasterColorConverter.Shutdown();

   // return the converted buffer.
   return rgbBuffer;
}

• The code below shows how a conversion can be done using user-defined tables:

[Visual Basic]

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ColorConversion

Private Function UserTablesConvertCmykToRgb(ByVal cmykBuffer As Byte(), ByVal width As Integer, ByVal height As Integer) As Byte()
' StartUp the ColorConversion.
RasterColorConverter.Startup()

' Initialize the Rgb buffer array
Dim rgbBuffer As Byte() = New Byte(cmykBuffer.Length - 1){}

' Initialize a new ConversionParameters class object.
Dim convParams As ConversionParameters = New ConversionParameters()

' Conversion with options.
' The conversion will be done with the options specified in the 
' params(variable)

' we want to use custom emulation tables 
convParams.Method = ConversionMethodFlags.UseCustomEmulationTables

' set the active conversion method 
convParams.ActiveMethod = ConversionMethodFlags.UseCustomEmulationTables

' set the emulation tables 
convParams.DestinationInputTable = "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\ET\src_rgb_image.tif"

' Initialize a new Converter object
Dim converter As RasterColorConverter = New RasterColorConverter()

Try
  ' Initialize the color conversion 
  converter.Start(ConversionColorFormat.Cmyk, ConversionColorFormat.Rgb, convParams)

  ' Convert the image buffer 
  converter.Convert(cmykBuffer, 0, rgbBuffer, 0, width, height, 0, 0)

  ' Stop the conversion 
  converter.Stop()
Catch ex As Exception
  MessageBox.Show(ex.Message)
  rgbBuffer = Nothing
End Try

' Shutdown the ColorConversion.
RasterColorConverter.Shutdown()

' return the converted buffer.
Return rgbBuffer
                   End Function

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ColorConversion;

private byte[] UserTablesConvertCmykToRgb(byte[] cmykBuffer, int width, int height)
{
   // StartUp the ColorConversion.
   RasterColorConverter.Startup();

   // Initialize the Rgb buffer array
   byte[] rgbBuffer = new byte[cmykBuffer.Length];

   // Initialize a new ConversionParameters class object.
   ConversionParameters convParams = new ConversionParameters();

   // Conversion with options.
   // The conversion will be done with the options specified in the 
   // params(variable)

   // we want to use custom emulation tables 
   convParams.Method = ConversionMethodFlags.UseCustomEmulationTables;

   // set the active conversion method 
   convParams.ActiveMethod = ConversionMethodFlags.UseCustomEmulationTables;

   // set the emulation tables 
   convParams.DestinationInputTable = @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\ET\src_rgb_image.tif";

   // Initialize a new Converter object
   RasterColorConverter converter = new RasterColorConverter();

   try
   {
      // Initialize the color conversion 
      converter.Start(ConversionColorFormat.Cmyk,
          ConversionColorFormat.Rgb,
          convParams);

      // Convert the image buffer 
      converter.Convert(cmykBuffer, 0, rgbBuffer, 0, width, height, 0, 0);

      // Stop the conversion 
      converter.Stop();
   }
   catch (Exception ex)
   {
      MessageBox.Show(ex.Message);
      rgbBuffer = null;
   }

   // Shutdown the ColorConversion.
   RasterColorConverter.Shutdown();

   // return the converted buffer.
   return rgbBuffer;
}