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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 
C++/CLI 
public ref class ConvertToColoredGrayCommand : public RasterCommand, IRasterCommand 

Example

Run the ConvertToColoredGrayCommand on an image with RedFactor = 300, GreenFactor = 590, BlueFactor = 110, RedGrayFactor = 500, GreenGrayFactor = 300, BlueGrayFactor = 200.

Visual BasicCopy Code
Public Sub ConvertToColoredGrayCommandExample()
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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, LeadtoolsExamples.Common.ImagesPath.Path + "Result.jpg", RasterImageFormat.Jpeg, 24)

   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void ConvertToColoredGrayCommandExample() 
{ 
   // Load an image 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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, LeadtoolsExamples.Common.ImagesPath.Path + "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 Introduction to Image Processing With LEADTOOLS.
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