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ColorLevelCommand Class
See Also  Members   Example 




Applies color leveling to an image. It changes the image shadows, midtones and highlights. This command is available in the Raster Pro and above toolkits.

Object Model





Syntax

Visual Basic (Declaration) 
Public Class ColorLevelCommand 
   Inherits RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As ColorLevelCommand
C# 
public class ColorLevelCommand : RasterCommand, IRasterCommand 
Managed Extensions for C++ 
public __gc class ColorLevelCommand : public RasterCommand, IRasterCommand 
C++/CLI 
public ref class ColorLevelCommand : public RasterCommand, IRasterCommand 

Example

Visual BasicCopy Code
ImageProcessing.Color.ColorLevelCommand
   Public Sub ColorLevelCommandExample()
      RasterCodecs.Startup()
      Dim codecs As New RasterCodecs()
      codecs.ThrowExceptionsOnInvalidImages = True

      Dim leadImage As RasterImage = codecs.Load("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Master.jpg")

      ' Prepare the command
      Dim blue As ColorLevelCommandData = New ColorLevelCommandData
      Dim master As ColorLevelCommandData = New ColorLevelCommandData
      ' Specify Image levels
      blue.MinimumInput = 20
      blue.MaximumInput = 200
      blue.MinimumOutput = 0
      blue.MaximumOutput = 255
      blue.Gamma = 100
      ' Master will cause the image to be Inversed
      master.MinimumInput = 0
      master.MaximumInput = 255
      master.MinimumOutput = 255
      master.MaximumOutput = 0
      master.Gamma = 100
      ' Level the Blue and Master channels
      Dim command As ColorLevelCommand = New ColorLevelCommand(master, Nothing, Nothing, blue, ColorLevelCommandFlags.Blue Or ColorLevelCommandFlags.Master)
      command.Run(leadImage)
      codecs.Save(leadImage, "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Result.jpg", RasterImageFormat.Jpeg, 24)

      RasterCodecs.Shutdown()
   End Sub
C#Copy Code
ImageProcessing.Color.ColorLevelCommand 
      public void ColorLevelCommandExample() 
      { 
         // Load an image 
         RasterCodecs.Startup(); 
         RasterCodecs codecs = new RasterCodecs(); 
         codecs.ThrowExceptionsOnInvalidImages = true; 
 
         RasterImage image = codecs.Load(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Master.jpg"); 
 
         // Prepare the command 
         ColorLevelCommandData blue    = new ColorLevelCommandData(); 
         ColorLevelCommandData master  = new ColorLevelCommandData(); 
         //Specify Image levels 
         blue.MinimumInput    = 20; 
         blue.MaximumInput    = 200; 
         blue.MinimumOutput   = 0; 
         blue.MaximumOutput   = 255; 
         blue.Gamma           = 100; 
         // Master will cause the image to be Inversed 
         master.MinimumInput  = 0; 
         master.MaximumInput  = 255; 
         master.MinimumOutput = 255; 
         master.MaximumOutput = 0; 
         master.Gamma         = 100; 
         // Level the Blue and Master channels 
         ColorLevelCommand command = new ColorLevelCommand(master, null, null, blue, ColorLevelCommandFlags.Blue | ColorLevelCommandFlags.Master); 
         command.Run(image); 
         codecs.Save(image, @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Result.jpg", RasterImageFormat.Jpeg, 24); 
 
         RasterCodecs.Shutdown(); 
      }

Remarks

  • The members of the ColorLevelCommandData class tell the ColorLevelCommand what constitutes shadows, midtones, and highlights and how to remap the shadows, midtones and highlights.
  • Control the amount of image balance and leveling by controlling the values of the MinimumInput, MaximumInput, MinimumOutput, MaximumOutput, and Gamma members of the ColorLevelCommandData class.
    • The MinimumInput property of the ColorLevelCommandData class defines what the method interprets as shadows for that color channel. Any value less than or equal to MinimumInput is considered a shadow.
    • The MaximumInput property of the ColorLevelCommandData class defines what the method interprets as highlights for that color channel. Any value greater than or equal to MaximumInput is considered a highlight.
    • The value of the MaximumInput property must be greater than the value of the MinimumInput property by at least 2.
    • Midtones are those values between MinimumInput and MaximumInput.
    • The MinimumOutput property is the value to which the shadows will be mapped.
    • The MaximumOutput property is the value to which the highlights will be mapped.
    • The Gamma property is used to modify the midtone values
  • If only ColorLevelCommandFlags.Master is set in the Flags property, then the rest of the channels will still be affected.
  • If the image is a grayscale image, then you must set ColorLevelCommandFlags.Master in the Flags property, otherwise the class will not have any effect.
  • If MinimumOutput > MaximumOutput then the image's shadows and highlights will be inverted.
  • This command supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
  • This command does not support signed data images.

For more information, refer to Changing Brightness and Contrast. For more information, refer to Correcting Colors.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Color.ColorLevelCommand

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also