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HistogramEqualize Method
See Also  Example
Leadtools.Services.ImageProcessing.ServiceContracts Namespace > IColorProcessingService Interface : HistogramEqualize Method



request
A DataContractAttribute containing the data that will be used in this HistogramEqualize operation.
request
A DataContractAttribute containing the data that will be used in this HistogramEqualize operation.
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 operation is useful for pre-processing images for the purpose of improving barcode recognition results.

Syntax

Visual Basic (Declaration) 
<OperationContractAttribute("HistogramEqualize")>
<FaultContractAttribute(DetailType=Leadtools.Services.Raster.FaultContracts.RasterFault, 
   Action="", 
   Name="", 
   Namespace="", 
   HasProtectionLevel=False)>
Overridable Function HistogramEqualize( _
   ByVal request As HistogramEqualizeRequest _
) As CommandResponse
Visual Basic (Usage)Copy Code
Dim instance As IColorProcessingService
Dim request As HistogramEqualizeRequest
Dim value As CommandResponse
 
value = instance.HistogramEqualize(request)
C# 
[OperationContractAttribute("HistogramEqualize")]
[FaultContractAttribute(DetailType=Leadtools.Services.Raster.FaultContracts.RasterFault, 
   Action="", 
   Name="", 
   Namespace="", 
   HasProtectionLevel=false)]
virtual CommandResponse HistogramEqualize( 
   HistogramEqualizeRequest request
)
C++/CLI 
[OperationContractAttribute("HistogramEqualize")]
[FaultContractAttribute(DetailType=Leadtools.Services.Raster.FaultContracts.RasterFault, 
   Action="", 
   Name="", 
   Namespace="", 
   HasProtectionLevel=false)]
virtual CommandResponse HistogramEqualize( 
   HistogramEqualizeRequest request
)

Parameters

request
A DataContractAttribute containing the data that will be used in this HistogramEqualize operation.

Return Value

A DataContractAttribute containing the modified image resulting from the HistogramEqualize operation.

Example

Visual BasicCopy Code
Public Sub HistogramEqualizeExample()
  Dim client As ColorProcessingServiceClient = New ColorProcessingServiceClient()
  Dim sourceBinaryData As RawBinaryData = New RawBinaryData()
  sourceBinaryData.Data = File.ReadAllBytes(LeadtoolsExamples.Common.ImagesPath.Path & "image1.cmp")

  Dim convertOptions As RasterConvertOptions = New RasterConvertOptions()

  convertOptions.Source = sourceBinaryData
  convertOptions.Destination = Nothing
  convertOptions.Format = RasterImageFormat.Bmp
  convertOptions.FirstPage = 1
  convertOptions.LastPage = 1
  convertOptions.BitsPerPixel = 24
  convertOptions.QualityFactor = 2

  Dim request As HistogramEqualizeRequest = New HistogramEqualizeRequest()

  request.ConvertOptions = convertOptions
  request.RegionData = Nothing
  request.Type = HistogramEqualizeType.Yuv

  Dim response As CommandResponse = client.HistogramEqualize(request)
  If Not response.Destination Is Nothing Then
    If TypeOf response.Destination Is RawBinaryData Then
       File.WriteAllBytes(LeadtoolsExamples.Common.ImagesPath.Path & "HistogramEqualize.bmp", (TryCast(response.Destination, RawBinaryData)).Data)
    End If
  End If

  client.Close()
End Sub
C#Copy Code
public void HistogramEqualizeExample() 
{ 
   ColorProcessingServiceClient client = new ColorProcessingServiceClient(); 
   RawBinaryData sourceBinaryData = new RawBinaryData(); 
   sourceBinaryData.Data = File.ReadAllBytes(LeadtoolsExamples.Common.ImagesPath.Path + "image1.cmp"); 
 
   RasterConvertOptions convertOptions = new RasterConvertOptions(); 
 
   convertOptions.Source = sourceBinaryData; 
   convertOptions.Destination = null; 
   convertOptions.Format = RasterImageFormat.Bmp; 
   convertOptions.FirstPage = 1; 
   convertOptions.LastPage = 1; 
   convertOptions.BitsPerPixel = 24; 
   convertOptions.QualityFactor = 2; 
 
   HistogramEqualizeRequest request = new HistogramEqualizeRequest(); 
 
   request.ConvertOptions = convertOptions; 
   request.RegionData = null; 
   request.Type = HistogramEqualizeType.Yuv; 
 
   CommandResponse response = client.HistogramEqualize(request); 
   if (response.Destination != null) 
   { 
      if (response.Destination is RawBinaryData) 
         File.WriteAllBytes(LeadtoolsExamples.Common.ImagesPath.Path + "HistogramEqualize.bmp", (response.Destination as RawBinaryData).Data); 
   } 
 
   client.Close(); 
}

Remarks

  • Previously this operation only equalized the number of pixels per gray level, using a gray level representation of the image. This operation is now obtained by setting HistogramEqualizeType.Gray for the Type property.
  • For the best results, set Type to HistogramEqualizeType.Yuv.
  • This operation can process the whole image or a region of the image.
  • This operation 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 operation does not support 32-bit grayscale images.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also

Applications developed with LEADTOOLS WCF components require runtime licenses. Server licensing is required for applications on a server. For more information, refer to: Imaging Pro/Document/Medical Features