LEADTOOLS Image Processing (Leadtools.ImageProcessing.Color assembly) Send comments on this topic. | Back to Introduction - All Topics | Help Version 17.0.3.29
HistogramEqualizeCommand Class
See Also  Members  



Linearizes the number of pixels, in an image, based on the specified color space. This can be used to bring out the detail in dark areas of an image. This function is useful for pre-processing images for the purpose of improving barcode recognition results. Supported in Silverlight, Windows Phone 7

Object Model

HistogramEqualizeCommand Class

Syntax

Visual Basic (Declaration) 
Public Class HistogramEqualizeCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As HistogramEqualizeCommand
C# 
public class HistogramEqualizeCommand : Leadtools.ImageProcessing.RasterCommand, IRasterCommand  
C++/CLI 
public ref class HistogramEqualizeCommand : public Leadtools.ImageProcessing.RasterCommand, IRasterCommand  

Example

Run the Leadtools.ImageProcessing.Color.HistogramEqualizeCommand on an image and apply histogram equalization with YUV color space.

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

   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg"))

   ' Prepare the command
   Dim command As HistogramEqualizeCommand = New HistogramEqualizeCommand
   'Histogram equalize the image.
   command.Type = HistogramEqualizeType.Yuv

   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
C#Copy Code
public void HistogramEqualizeCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg"));

      // Prepare the command
      HistogramEqualizeCommand command = new HistogramEqualizeCommand();
      //Histogram equalize the image.
      command.Type   = HistogramEqualizeType.Yuv;
      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";
}
SilverlightCSharpCopy Code
public void HistogramEqualizeCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   HistogramEqualizeCommand command = new HistogramEqualizeCommand();
   //Histogram equalize the image.
   command.Type   = HistogramEqualizeType.Yuv;
   command.Run(image);
   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}
SilverlightVBCopy Code
Public Sub HistogramEqualizeCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim command As HistogramEqualizeCommand = New HistogramEqualizeCommand()
   'Histogram equalize the image.
   command.Type = HistogramEqualizeType.Yuv
   command.Run(image)
   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   image.Dispose()
End Sub

Remarks

  • Previously this class only equalized the number of pixels per gray level, using a gray level representation of the image. This functionality is now obtained by passing HistogramEqualizeType.Gray for the Type property.
  • For the best results, set Type to HistogramEqualizeType.Yuv
  • This class can process the whole image or a region of the image.
  • 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.
For more information, refer to Changing Brightness and Contrast.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Color.HistogramEqualizeCommand

Requirements

Target Platforms: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)

See Also

Reference

HistogramEqualizeCommand 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
ChannelMixerCommand Class
Leadtools.ImageProcessing.Effects.DeinterlaceCommand
DesaturateCommand Class
Leadtools.ImageProcessing.Effects.EdgeDetectStatisticalCommand
LightControlCommand Class
Leadtools.ImageProcessing.Effects.SmoothEdgesCommand
LocalHistogramEqualizeCommand Class
AddWeightedCommand Class
ColorMergeCommand Class
ColorSeparateCommand Class
MultiplyCommand Class
AutoColorLevelCommand Class
ColorLevelCommand Class
Leadtools.ImageProcessing.Core.CorrelationListCommand
GrayScaleToDuotoneCommand Class
GrayScaleToMultitoneCommand Class
Leadtools.ImageProcessing.Core.HolePunchRemoveCommand
SelectiveColorCommand Class
Leadtools.ImageProcessing.Effects.SkeletonCommand
ChangeHueSaturationIntensityCommand Class
ColorReplaceCommand Class
ColorThresholdCommand Class
MathematicalFunctionCommand Class
SegmentCommand Class
AdaptiveContrastCommand Class
ApplyMathematicalLogicCommand Class
ColorIntensityBalanceCommand Class
Leadtools.ImageProcessing.Core.ColorizeGrayCommand
ContrastBrightnessIntensityCommand Class
Leadtools.ImageProcessing.Core.DigitalSubtractCommand
DynamicBinaryCommand Class
Leadtools.ImageProcessing.Effects.EdgeDetectEffectCommand
Leadtools.ImageProcessing.SpecialEffects.FunctionalLightCommand
Leadtools.ImageProcessing.Core.MultiscaleEnhancementCommand
Leadtools.ImageProcessing.Core.SelectDataCommand
Leadtools.ImageProcessing.Core.ShiftDataCommand