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ConvertToColoredGrayCommand Class
See Also  Members   Example 




Converts an image to a grayscale image, then enhances the color components based on the class properties. This class is available in the Document Toolkits.

Syntax

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

Example

Visual BasicCopy Code
ImageProcessing.Color.ConvertToColoredGrayCommand
   Public Sub ConvertToColoredGrayCommandExample()
      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 command As ConvertToColoredGrayCommand = New ConvertToColoredGrayCommand
      'These arguments will transform the image into a grayscale image.
      command.RedFactor = 300
      command.GreenFactor = 590
      command.BlueFactor = 110
      command.RedGrayFactor = 500
      command.GreenGrayFactor = 300
      command.BlueGrayFactor = 200
      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.ConvertToColoredGrayCommand 
      public void ConvertToColoredGrayCommandExample() 
      { 
         // 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 
         ConvertToColoredGrayCommand command = new ConvertToColoredGrayCommand(); 
         //These arguments will transform the image into a grayscale image. 
         command.RedFactor       = 300;  
         command.GreenFactor     = 590; 
         command.BlueFactor      = 110; 
         command.RedGrayFactor   = 500; 
         command.GreenGrayFactor = 300; 
         command.BlueGrayFactor  = 200; 
         command.Run(image); 
         codecs.Save(image, @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Result.jpg", RasterImageFormat.Jpeg, 24); 
 
         RasterCodecs.Shutdown(); 
      }

Remarks

  • This class is more general than the GrayScaleExtendedCommand class. The ConvertToColoredGrayCommand class can be used to give images a "sepia" look by adding a blue or brown color.

  • RedFactor + GreenFactor + BlueFactor must equal 1000. (Internally the values are divided by 1000).

  • For each pixel in the image the red, green and blue values are modified by the RedFactor, GreenFactor and BlueFactor properties, respectively. This allows the user to give more weight to one color, essentially enhancing that color, before the pixel is converted to grayscale.
  • For example, if this class is used with the RedFactor set to 500, the GreenFactor set to 250 and the BlueFactor set to 250, the red value of each pixel will get 50 percent of the weight when determining the grayscale value. The green value will get 25 percent of the weight and the blue value will get 25 percent of the weight when determining the grayscale value. This highlights or enhances the red in the image, prior to conversion to grayscale. Upon conversion to grayscale, the red, green and blue components of the output pixel are the same. Call this value G. Therefore, the RGB values for the pixel would be (G, G, G).
  • Once the grayscale value for the pixel has been obtained, the red component of the output pixel can be further modified using the RedGrayFactor value. The equation for this can be seen below:
  • The green and blue components are found similarly, using the GreenGrayFactor and the BlueGrayFactor values, respectively.
  • Please note that the RedGrayFactor, GreenGrayFactor and BlueGrayFactor values can be negative. A negative value results in a decrease in pixel intensity. A positive value results in an increase in pixel intensity.
  • If RedGrayFactor = GreenGrayFactor = BlueGrayFactor = 0, then the output is the same as the output from the GrayScaleExtendedCommand method.
  • This class 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 class does not support signed data images.
  • This command does not support 32-bit grayscale images.
For more information, refer to Processing an Image.
For more information, refer to Grayscale Images.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Color.ConvertToColoredGrayCommand

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