GrayscaleCommand Class

Converts a 1-, 4-, 8-, 16-, 24-, or 32-bit image to an 8-bit, 12-bit, or 16-bit grayscale image.

Object Model

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public class GrayscaleCommand : RasterCommand, IRasterCommand

'Declaration
 
Public Class GrayscaleCommand 
   Inherits RasterCommand
   Implements IRasterCommand

'Usage
 
Dim instance As GrayscaleCommand

public sealed class GrayscaleCommand : IRasterCommand

function Leadtools.ImageProcessing.GrayscaleCommand()

public ref class GrayscaleCommand : public RasterCommand, IRasterCommand

Remarks

Support for 12 and 16-bit grayscale images is available only in the Document/Medical Imaging editions.

The resulting image can be an 8-bit, 12-bit, or 16-bit grayscale image. Once the function is complete, the RasterImage.GrayscaleMode property will indicate the type of grayscale image.

When converting to 12-bit or 16-bit grayscale, the RasterImage.GetLookupTable is not used. When converting to 8-bit grayscale, the RasterImage.GetLookupTable is used to get the RGB for each input pixel. The grayscale value corresponding to that RGB triple is used in the destination image.

This method does not support signed images.

For more information, refer to Introduction to Image Processing With LEADTOOLS.

For more information, refer to Grayscale Images.

Example

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Public Sub GrayscaleCommandExample()
      Dim codecs As RasterCodecs = New RasterCodecs()

      Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
      Dim destFileName8 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_grayscale8.jpg")
      Dim destFileName12 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_grayscale12.jpg")
      Dim destFileName16 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_grayscale16.jpg")

      ' Load the source image from disk as 24-bits/pixel
      Dim image As RasterImage = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1)

      ' Check the grayscale mode
      Console.WriteLine("Grsyscale mode of original image = {0}", image.GrayscaleMode)

      ' Convert to 8-bit grayscale
      Dim command As GrayscaleCommand = New GrayscaleCommand()
      command.BitsPerPixel = 8
      command.Run(image)

      ' Check the grayscale mode
      Console.WriteLine("Grsyscale mode after grayscale command with 8 bpp = {0}", image.GrayscaleMode)

      ' Save it to disk

      codecs.Options.Jpeg.Save.QualityFactor = 2
      codecs.Save(image, destFileName8, RasterImageFormat.Jpeg, 8)
      image.Dispose()

      ' Load the image again this time grayscale to 12-bits/pixel
      image = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1)
      command.BitsPerPixel = 12
      command.Run(image)
      Console.WriteLine("Grsyscale mode after grayscale command with 12 bpp = {0}", image.GrayscaleMode)
      codecs.Options.Jpeg.Save.QualityFactor = 2
      codecs.Save(image, destFileName12, RasterImageFormat.Jpeg, 12)
      image.Dispose()

      ' Load the image again this time grayscale to 16-bits/pixel
      image = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1)
      command.BitsPerPixel = 16
      command.Run(image)
      Console.WriteLine("Grsyscale mode after grayscale command with 16 bpp = {0}", image.GrayscaleMode)

      ' When saving 16-bit jpegs, you must use lossless quality factor
      codecs.Options.Jpeg.Save.QualityFactor = 0
      codecs.Save(image, destFileName16, RasterImageFormat.Jpeg, 16)
      image.Dispose()

      ' Clean Up
      image.Dispose()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

public void GrayscaleCommandExample()
   {
      RasterCodecs codecs = new RasterCodecs();

      string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp");
      string destFileName8 = Path.Combine(LEAD_VARS.ImagesDir,"Image1_grayscale8.jpg");
      string destFileName12 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_grayscale12.jpg");
      string destFileName16 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_grayscale16.jpg");

      // Load the source image from disk as 24-bits/pixel
      RasterImage image = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1);

      // Check the grayscale mode
      Console.WriteLine("Grsyscale mode of original image = {0}", image.GrayscaleMode);

      // Convert to 8-bit grayscale
      GrayscaleCommand command = new GrayscaleCommand();
      command.BitsPerPixel = 8;
      command.Run(image);

      // Check the grayscale mode
      Console.WriteLine("Grsyscale mode after grayscale command with 8 bpp = {0}", image.GrayscaleMode);

      // Save it to disk

      codecs.Options.Jpeg.Save.QualityFactor = 2;
      codecs.Save(image, destFileName8, RasterImageFormat.Jpeg, 8);
      image.Dispose();

      // Load the image again this time grayscale to 12-bits/pixel
      image = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1);
      command.BitsPerPixel = 12;
      command.Run(image);
      Console.WriteLine("Grsyscale mode after grayscale command with 12 bpp = {0}", image.GrayscaleMode);
      codecs.Options.Jpeg.Save.QualityFactor = 2;
      codecs.Save(image, destFileName12, RasterImageFormat.Jpeg, 12);
      image.Dispose();

      // Load the image again this time grayscale to 16-bits/pixel
      image = codecs.Load(srcFileName, 24, CodecsLoadByteOrder.Bgr, 1, 1);
      command.BitsPerPixel = 16;
      command.Run(image);
      Console.WriteLine("Grsyscale mode after grayscale command with 16 bpp = {0}", image.GrayscaleMode);

      // When saving 16-bit jpegs, you must use lossless quality factor
      codecs.Options.Jpeg.Save.QualityFactor = 0;
      codecs.Save(image, destFileName16, RasterImageFormat.Jpeg, 16);
      image.Dispose();

      // Clean Up
      image.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

RasterCommandExamples.prototype.GrayscaleCommandExample = function ( )
{
    Tools.SetLicense ( ) ;
    with (Leadtools) {
        with (Leadtools.Codecs) {
            with (Leadtools.ImageProcessing) {
                var codecs = new RasterCodecs();

                var srcFileName = "Assets\\Image1.cmp";
                var destFileName8 = "Image1_grayscale8.jpg";
                var destFileName12 = "Image1_grayscale12.jpg";
                var destFileName16 = "Image1_grayscale16.jpg";
                var image;
                var command;
                var loadFile;
                // Load the source image from disk as 24-bits/pixel
                return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (file) {
                    loadFile = file;
                    return codecs.loadAsync(LeadStreamFactory.create(loadFile), 24, CodecsLoadByteOrder.bgr, 1, 1)
                })
            .then(function (img) {
                image = img;

                // Check the grayscale mode
                console.info("Grsyscale mode of original image = ", image.grayscaleMode);

                // Convert to 8-bit grayscale
                command = new GrayscaleCommand();
                command.bitsPerPixel = 8;
                command.run(image);

                // Check the grayscale mode
                console.info("Grsyscale mode after grayscale command with 8 bpp = ", image.grayscaleMode);

                // Save it to disk
                codecs.options.jpeg.save.qualityFactor = 2;
                return Tools.AppLocalFolder().createFileAsync(destFileName8)
            })
            .then(function (saveFile) {
                return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.jpeg, 8)
            })
            .then(function () {
                image.close();

                // Load the image again this time grayscale to 12-bits/pixel
                return codecs.loadAsync(LeadStreamFactory.create(loadFile), 24, CodecsLoadByteOrder.bgr, 1, 1)
            })
                .then(function (img) {
                    image = img;
                    command.bitsPerPixel = 12;
                    command.run(image);
                    console.info("Grsyscale mode after grayscale command with 12 bpp = ", image.grayscaleMode);
                    codecs.options.jpeg.save.qualityFactor = 2;
                    return Tools.AppLocalFolder().createFileAsync(destFileName12)
                })
            .then(function (saveFile) {
                codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.jpeg, 12)
            })
            .then(function () {
                image.close();

                // Load the image again this time grayscale to 16-bits/pixel
                return codecs.loadAsync(LeadStreamFactory.create(loadFile), 24, CodecsLoadByteOrder.bgr, 1, 1)
            })
            .then(function (img) {
                image = img;
                command.bitsPerPixel = 16;
                command.run(image);
                console.info("Grsyscale mode after grayscale command with 16 bpp = ", image.grayscaleMode);

                // When saving 16-bit jpegs, you must use lossless quality factor
                codecs.options.jpeg.save.qualityFactor = 0;
                return Tools.AppLocalFolder().createFileAsync(destFileName16)
            })
            .then(function (saveFile) {
                return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.Jpeg, 16)
            })
            .then(function () {
                image.close();
                codecs.close();
            });
            }
        }
    }
}

[TestMethod]
public async Task GrayscaleCommandExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = @"Assets\Image1.cmp";
   string destFileName8 = @"Image1_grayscale8.jpg";
   string destFileName12 = @"Image1_grayscale12.jpg";
   string destFileName16 = @"Image1_grayscale16.jpg";

   // Load the source image from disk as 24-bits/pixel
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile), 24, CodecsLoadByteOrder.Bgr, 1, 1);

   // Check the grayscale mode
   Debug.WriteLine("Grsyscale mode of original image = {0}", image.GrayscaleMode);

   // Convert to 8-bit grayscale
   GrayscaleCommand command = new GrayscaleCommand();
   command.BitsPerPixel = 8;
   command.Run(image);

   // Check the grayscale mode
   Debug.WriteLine("Grsyscale mode after grayscale command with 8 bpp = {0}", image.GrayscaleMode);

   // Save it to disk

   codecs.Options.Jpeg.Save.QualityFactor = 2;
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName8);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, 8);
   image.Dispose();

   // Load the image again this time grayscale to 12-bits/pixel
   image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile), 24, CodecsLoadByteOrder.Bgr, 1, 1);
   command.BitsPerPixel = 12;
   command.Run(image);
   Debug.WriteLine("Grsyscale mode after grayscale command with 12 bpp = {0}", image.GrayscaleMode);
   codecs.Options.Jpeg.Save.QualityFactor = 2;
   saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName12);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, 12);
   image.Dispose();

   // Load the image again this time grayscale to 16-bits/pixel
   image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile), 24, CodecsLoadByteOrder.Bgr, 1, 1);
   command.BitsPerPixel = 16;
   command.Run(image);
   Debug.WriteLine("Grsyscale mode after grayscale command with 16 bpp = {0}", image.GrayscaleMode);

   // When saving 16-bit jpegs, you must use lossless quality factor
   codecs.Options.Jpeg.Save.QualityFactor = 0;
   saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName16);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, 16);
   image.Dispose();

   // Clean Up
   image.Dispose();
}

public void GrayscaleCommandExample(RasterImage image, Stream destStream8, Stream destStream12, Stream destStream16)
{
   RasterCodecs codecs = new RasterCodecs();
   RasterImage temp = image.Clone();
   // Check the grayscale mode
   Debug.WriteLine("Grsyscale mode of original image = {0}", image.GrayscaleMode);

   // Convert to 8-bit grayscale
   GrayscaleCommand command = new GrayscaleCommand();
   command.BitsPerPixel = 8;
   command.Run(image);

   // Check the grayscale mode
   Debug.WriteLine("Grsyscale mode after grayscale command with 8 bpp = {0}", image.GrayscaleMode);
   Debug.Assert(image.GrayscaleMode == RasterGrayscaleMode.OrderedInverse || image.GrayscaleMode == RasterGrayscaleMode.OrderedNormal);

   // Save it to disk
   codecs.Options.Jpeg.Save.QualityFactor = 2;
   codecs.Save(image, destStream8, RasterImageFormat.Jpeg, 8);
   image.Dispose();

   // this time grayscale to 12-bits/pixel
   image = temp.Clone();
   command.BitsPerPixel = 12;
   command.Run(image);
   Debug.WriteLine("Grsyscale mode after grayscale command with 12 bpp = {0}", image.GrayscaleMode);
   codecs.Options.Jpeg.Save.QualityFactor = 2;
   codecs.Save(image, destStream12, RasterImageFormat.Jpeg, 12);
   image.Dispose();

   // this time grayscale to 16-bits/pixel
   image = temp.Clone();
   command.BitsPerPixel = 16;
   command.Run(image);
   Debug.WriteLine("Grsyscale mode after grayscale command with 16 bpp = {0}", image.GrayscaleMode);

   // When saving 16-bit jpegs, you must use lossless quality factor
   codecs.Options.Jpeg.Save.QualityFactor = 0;
   codecs.Save(image, destStream16, RasterImageFormat.Jpeg, 16);
   image.Dispose();

   // Clean Up
   temp.Dispose();
}

Public Sub GrayscaleCommandExample(ByVal image As RasterImage, ByVal destStream8 As Stream, ByVal destStream12 As Stream, ByVal destStream16 As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()
   Dim temp As RasterImage = image.Clone()
   ' Check the grayscale mode
   Debug.WriteLine("Grsyscale mode of original image = {0}", image.GrayscaleMode)

   ' Convert to 8-bit grayscale
   Dim command As GrayscaleCommand = New GrayscaleCommand()
   command.BitsPerPixel = 8
   command.Run(image)

   ' Check the grayscale mode
   Debug.WriteLine("Grsyscale mode after grayscale command with 8 bpp = {0}", image.GrayscaleMode)
   Debug.Assert(image.GrayscaleMode = RasterGrayscaleMode.OrderedInverse OrElse image.GrayscaleMode = RasterGrayscaleMode.OrderedNormal)

   ' Save it to disk
   codecs.Options.Jpeg.Save.QualityFactor = 2
   codecs.Save(image, destStream8, RasterImageFormat.Jpeg, 8)
   image.Dispose()

   ' this time grayscale to 12-bits/pixel
   image = temp.Clone()
   command.BitsPerPixel = 12
   command.Run(image)
   Debug.WriteLine("Grsyscale mode after grayscale command with 12 bpp = {0}", image.GrayscaleMode)
   codecs.Options.Jpeg.Save.QualityFactor = 2
   codecs.Save(image, destStream12, RasterImageFormat.Jpeg, 12)
   image.Dispose()

   ' this time grayscale to 16-bits/pixel
   image = temp.Clone()
   command.BitsPerPixel = 16
   command.Run(image)
   Debug.WriteLine("Grsyscale mode after grayscale command with 16 bpp = {0}", image.GrayscaleMode)

   ' When saving 16-bit jpegs, you must use lossless quality factor
   codecs.Options.Jpeg.Save.QualityFactor = 0
   codecs.Save(image, destStream16, RasterImageFormat.Jpeg, 16)
   image.Dispose()

   ' Clean Up
   temp.Dispose()
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

GrayscaleCommand Members
Leadtools.ImageProcessing Namespace
Leadtools.Drawing.RasterPaintCallbacks
Implementing custom paint