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Distance Property
See Also  Example
Leadtools.ImageOptimization Namespace > ImageOptimizerOptions Structure : Distance Property



Gets or sets a value that represents the distance between image colors to be reduced in the image optimization operation.

Syntax

Visual Basic (Declaration) 
Public Property Distance As Integer
Visual Basic (Usage)Copy Code
Dim instance As ImageOptimizerOptions
Dim value As Integer
 
instance.Distance = value
 
value = instance.Distance
C# 
public int Distance {get; set;}
C++/CLI 
public:
property int Distance {
   int get();
   void set (int value);
}

Return Value

The Distance value can be a value between 0 and 255, where:
  • 0 means no additional reduction.
  • 1 to 255 further reduction based on the color distance.
The default value is 8.

Example

This example will optimize a Gif image file and then save it to a separate folder

Visual BasicCopy Code
Public Sub TestGifImageOptimizer()
   ' Initialize the RasterCodecs class
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()

   ' The input and output location
   Dim inputFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "eye.gif"
   Dim outputFolder As String = LeadtoolsExamples.Common.ImagesPath.Path + "Optimized Images"

   ' Initialize a new Optimizer object
   Dim optimizer As ImageOptimizer = New ImageOptimizer()

   ' Optimization Options
   Dim options As ImageOptimizerOptions = ImageOptimizerOptions.Default

   ' Set custom optimization options
   options.Distance = 20
   options.Percent = 15
   options.PickSamePalette = True

   ' Load the input file into a byte memory array
   Dim orgBuffer() As Byte = File.ReadAllBytes(inputFileName)

   ' Optimize this buffer
   Dim optBuffer() As Byte = optimizer.OptimizeBuffer(codecs, orgBuffer, 0, orgBuffer.Length, options, Nothing)

   ' Save this image into the output folder
   ' Make sure the output folder exists
   If (Not Directory.Exists(outputFolder)) Then
      Directory.CreateDirectory(outputFolder)
   End If

   ' Get the name of the output file from the input file
   Dim outputFileName As String = Path.Combine(outputFolder, Path.GetFileName(inputFileName))

   ' Save the optimized buffer to the output file
   Using fs As FileStream = File.Create(outputFileName)
      fs.Write(optBuffer, 0, optBuffer.Length)
   End Using

   ' Compare the original image size with the optimized size
   Dim orgSize As Long = New FileInfo(inputFileName).Length
   Dim optSize As Long = New FileInfo(outputFileName).Length
   Dim percentage As Integer = CType(CType(optSize * 100.0 / orgSize, Double), Integer)

   Dim message As String = String.Format( _
      "Original image size: {0} KB{1}Optimized image size: {2} KB{1}Percentage: {3}%", _
      orgSize / 1024, Environment.NewLine, optSize / 1024, _
      100 - percentage)
   MessageBox.Show(message)

   'shutdown the RasterCodecs class.
   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void TestGifImageOptimizer( ) 
{ 
   // Initialize the RasterCodecs class 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // The input and output location 
   string inputFileName = LeadtoolsExamples.Common.ImagesPath.Path + "eye.gif"; 
   string outputFolder = LeadtoolsExamples.Common.ImagesPath.Path + "OptimizedImages"; 
 
   // Initialize a new Optimizer object 
   ImageOptimizer optimizer = new ImageOptimizer(); 
 
   // Optimization Options 
   ImageOptimizerOptions options = ImageOptimizerOptions.Default; 
 
   // Set custom optimization options 
   options.Distance = 20; 
   options.Percent = 15; 
   options.PickSamePalette = true; 
 
   // Load the input file into a byte memory array 
   byte[] orgBuffer = File.ReadAllBytes(inputFileName); 
 
   // Optimize this buffer 
   byte[] optBuffer = optimizer.OptimizeBuffer(codecs, orgBuffer, 0, orgBuffer.Length, options, null); 
 
   // Save this image into the output folder 
   // Make sure the output folder exists 
   if(!Directory.Exists(outputFolder)) 
      Directory.CreateDirectory(outputFolder); 
 
   // Get the name of the output file from the input file 
   string outputFileName = Path.Combine(outputFolder, Path.GetFileName(inputFileName)); 
 
   // Save the optimized buffer to the output file 
   using(FileStream fs = File.Create(outputFileName)) 
      fs.Write(optBuffer, 0, optBuffer.Length); 
 
   // Compare the original image size with the optimized size 
   long orgSize = new FileInfo(inputFileName).Length; 
   long optSize = new FileInfo(outputFileName).Length; 
   int percentage = (int)((double)optSize * 100.0 / orgSize); 
 
   string message = string.Format( 
      "Original image size: {0} KB{1}Optimized image size: {2} KB{1}Percentage: {3}%", 
      orgSize / 1024, Environment.NewLine, optSize / 1024, 
      100 - percentage); 
   MessageBox.Show(message); 
 
   //shutdown the RasterCodecs class. 
   RasterCodecs.Shutdown(); 
}

Remarks

The Distance value will be used if the original image format is one of the following:
  1. Png File:
  2. Gif File:
  3. Bmp File
If the image is a 16-, 24-, or 32-bit BMP image, the real number of colors used in the image is calculated and when possible the image is saved with lower bits per pixel. If the image is a 1-, 4-, or 8-bits per pixel BMP image, the Percent and Distance are used.

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also