Distance Property

Summary

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

Syntax
C#
VB
C++
public int Distance { get; set; } 
  
Public Property Distance As Integer 
public: 
property int Distance { 
   int get(); 
   void set (    int ); 
} 

Property 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.

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-bit, 24-bit, 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-bit, 4-bit, or 8-bits per pixel BMP image, the Percent and Distance are used.

Example

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

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageOptimization; 
 
public void TestGifImageOptimizer() 
{ 
   // Initialize the RasterCodecs class 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // The input and output location 
   string inputFileName = Path.Combine(LEAD_VARS.ImagesDir, "eye.gif"); 
   string outputFolder = Path.Combine(LEAD_VARS.ImagesDir, "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. 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageOptimization 
'''Imports Leadtools.Support.Examples 
 
Public Sub TestGifImageOptimizer() 
   ' Initialize the RasterCodecs class 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   ' The input and output location 
   Dim inputFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "eye.gif") 
   Dim outputFolder As String = Path.Combine(LEAD_VARS.ImagesDir, "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. 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class 

Requirements

Target Platforms

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