JpegQualityFactor Property

Summary

Gets or sets a value that represents the quality factor to be used when optimizing an image.

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

Property Value

The JpegQualityFactor is a number used to balance between loss and quality during compression. You can set a value from 2 to 255, where 2 represents the highest quality and 255 represents the most compression. The default value is 35.

Remarks

The JpegQualityFactor is used only if the original image format is one of the following Jpeg formats:

Example
C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageOptimization; 
 
public void TestJpegImageOptimizer() 
{ 
   // Initialize the RasterCodecs class 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // The input and output location 
   string inputFileName = Path.Combine(LEAD_VARS.ImagesDir, "Cannon.jpg"); 
   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.JpegQualityFactor = 255; 
   options.JpegColorSpace = ImageOptimizerJpegColorSpace.JpegColorSpace422; 
 
   // Load the input file into a memory byte array 
   byte[] orgBuffer = File.ReadAllBytes(inputFileName); 
 
   // Optimize this buffer 
   byte[] optBuffer = optimizer.OptimizeBuffer(codecs, orgBuffer, 0, orgBuffer.Length, options, OptimizeBufferProgress); 
 
   // 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 bool OptimizeBufferProgress(int percent) 
{ 
   Console.WriteLine(string.Format("{0}%", percent)); 
   return true; 
} 
 
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 TestJpegImageOptimizer() 
   ' Initialize the RasterCodecs class 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   ' The input and output location 
   Dim inputFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Cannon.jpg") 
   Dim outputFolder As String = Path.Combine(LEAD_VARS.ImagesDir, "OptimizedImages") 
 
   ' Initialize a new Optimizer object 
   Dim optimizer As ImageOptimizer = New ImageOptimizer() 
 
   ' Optimization Options 
   Dim options As ImageOptimizerOptions = ImageOptimizerOptions.Default 
 
   ' Set custom optimization options 
   options.JpegQualityFactor = 255 
   options.JpegColorSpace = ImageOptimizerJpegColorSpace.JpegColorSpace422 
 
   ' Load the input file into a memory byte array 
   Dim orgBuffer() As Byte = File.ReadAllBytes(inputFileName) 
 
   ' Optimize this buffer 
   Dim optBuffer() As Byte = optimizer.OptimizeBuffer(codecs, orgBuffer, 0, orgBuffer.Length, options, AddressOf OptimizeBufferProgress) 
 
   ' 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 Shared Function OptimizeBufferProgress(ByVal percent As Integer) As Boolean 
   'Console.WriteLine(String.Format("{0}%", percent)) 
   Return True 
End Function 
 
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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