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

C#
Visual Basic
WinRT C#
Java
Objective-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

@interface LTGrayscaleCommand : LTRasterCommand

public class GrayscaleCommand extends RasterCommand

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.

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

For more information, refer to Grayscale Images.

Example

This example will load a 24-bit image then convert it to a grayscale image with 8, 12 and 16 bits/pixel

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

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Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing

      
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

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;

      
public void GrayscaleCommandExample()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = Path.Combine(ImagesPath.Path, "Image1.cmp");
   string destFileName8 = Path.Combine(ImagesPath.Path,"Image1_grayscale8.jpg");
   string destFileName12 = Path.Combine(ImagesPath.Path, "Image1_grayscale12.jpg");
   string destFileName16 = Path.Combine(ImagesPath.Path, "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
   codecs.Dispose();
}

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();
            });
            }
        }
    }
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;

      
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();
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Examples;
using Leadtools.ImageProcessing;
using Leadtools.Windows.Media;

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();
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.Windows.Media

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

Reference

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