LocalHistogramEqualizeCommand Class

C#
Visual Basic
WinRT C#
Java
Objective-C
WinRT JavaScript
C++

public class LocalHistogramEqualizeCommand : Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

'Declaration

Public Class LocalHistogramEqualizeCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements Leadtools.ImageProcessing.IRasterCommand

'Usage

Dim instance As LocalHistogramEqualizeCommand

public sealed class LocalHistogramEqualizeCommand : Leadtools.ImageProcessing.IRasterCommand

@interface LTLocalHistogramEqualizeCommand : LTRasterCommand

public class LocalHistogramEqualizeCommand extends RasterCommand

function Leadtools.ImageProcessing.Color.LocalHistogramEqualizeCommand()

public ref class LocalHistogramEqualizeCommand : public Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

This class applies the histogram equalizer locally on the image. The image is divided into local rectangles of dimension (Width, Height). The number of pixels inside each local rectangle are linearized according the histogram calculated for an extended rectangle around each local rectangle. The extended rectangles are of dimension:
((Width+2 * WidthExtension) , ( Height + 2 * HeightExtension)).

For an example, see the following drawing:

A rectangle and its associated extension, where the histogram is calculated.
Use this class to bring out details in an image that has portions that are too dark or too bright. An example of this is a picture taken with a flashlight in a dark room. In such a picture, the subject receives good light while the background is very dark. The application of the local histogram brings out details, but creates a blocky artifact. Use Smooth to reduce the blockiness of the result.
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 command does not support 32-bit grayscale images.
This command supports signed/unsigned data images.

For more information, refer to Changing Brightness and Contrast.

Run the LocalHistogramEqualizeCommand on an image.

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

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing.Color

   
Public Sub LocalHistogramEqualizeCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True
   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"))

   ' Prepare the command
   Dim command As LocalHistogramEqualizeCommand = New LocalHistogramEqualizeCommand
   command.Width = 15
   command.Height = 15
   command.WidthExtension = 100
   command.HeightExtension = 100
   command.Smooth = 0
   command.Type = HistogramEqualizeType.Yuv
   ' Local Histogram equalize the image.
   command.Run(leadImage)
   codecs.Save(leadImage, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24)

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.Color;

      
public void LocalHistogramEqualizeCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"));

   // Prepare the command
   LocalHistogramEqualizeCommand command = new LocalHistogramEqualizeCommand();
   command.Width           = 15;
   command.Height          = 15;
   command.WidthExtension  = 100;
   command.HeightExtension = 100;
   command.Smooth          = 0;
   command.Type            = HistogramEqualizeType.Yuv;
   // Local Histogram equalize the image.
   command.Run(image);
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24);

}

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

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

      
public async Task LocalHistogramEqualizeCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Prepare the command
   LocalHistogramEqualizeCommand command = new LocalHistogramEqualizeCommand();
   command.Width           = 15;
   command.Height          = 15;
   command.WidthExtension  = 100;
   command.HeightExtension = 100;
   command.Smooth          = 0;
   command.Type            = HistogramEqualizeType.Yuv;
   // Local Histogram equalize the image.
   command.Run(image);

   string destFileName = @"result.jpg";
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, 0);
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing.Color;
using Leadtools.Examples;

public void LocalHistogramEqualizeCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   LocalHistogramEqualizeCommand command = new LocalHistogramEqualizeCommand();
   command.Width           = 15;
   command.Height          = 15;
   command.WidthExtension  = 100;
   command.HeightExtension = 100;
   command.Smooth          = 0;
   command.Type            = HistogramEqualizeType.Yuv;
   // Local Histogram equalize the image.
   command.Run(image);
   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing.Color

Public Sub LocalHistogramEqualizeCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim command As LocalHistogramEqualizeCommand = New LocalHistogramEqualizeCommand()
   command.Width = 15
   command.Height = 15
   command.WidthExtension = 100
   command.HeightExtension = 100
   command.Smooth = 0
   command.Type = HistogramEqualizeType.Yuv
   ' Local Histogram equalize the image.
   command.Run(image)
   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   image.Dispose()
End Sub

Target Platforms

Reference

LocalHistogramEqualizeCommand Members
Leadtools.ImageProcessing.Color Namespace
Changing Brightness and Contrast
ChangeIntensityCommand Class
GammaCorrectCommand Class
ChangeContrastCommand Class
HistogramContrastCommand Class
StretchIntensityCommand Class
RemapIntensityCommand Class
InvertCommand Class
ChangeHueCommand Class
ChangeSaturationCommand Class
Leadtools.ImageProcessing.FillCommand
HistogramCommand Class
Leadtools.ImageProcessing.Core.WindowLevelCommand
AutoColorLevelCommand Class
ColorLevelCommand Class
Leadtools.ImageProcessing.Core.CorrelationListCommand
GrayScaleToDuotoneCommand Class
GrayScaleToMultitoneCommand Class
Leadtools.ImageProcessing.Core.HolePunchRemoveCommand
SelectiveColorCommand Class
Leadtools.ImageProcessing.Effects.SkeletonCommand