JpegQualityFactor Property

Visual Basic
C#
Objective-C
Java
C++

public int JpegQualityFactor {get; set;}

'Declaration
 
Public Property JpegQualityFactor As Integer

'Usage
 
Dim instance As ImageOptimizerOptions
Dim value As Integer
 
instance.JpegQualityFactor = value
 
value = instance.JpegQualityFactor

public:
property int JpegQualityFactor {
   int get();
   void set (    int value);
}

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.

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

RasterImageFormat.Jpeg, Bits per pixel: 8 for grayscale, 24 for color.
RasterImageFormat.Jpeg411, Bits per pixel: 8 for grayscale, 24 for color.
RasterImageFormat.Jpeg422, Bits per pixel: 8 for grayscale, 24 for color.
RasterImageFormat.ExifJpeg411, Bits per pixel: 24 (color only).
RasterImageFormat.ExifJpeg422, Bits per pixel: 24 (color only).

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

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, 0, 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

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";
}

Target Platforms

Reference

ImageOptimizerOptions Structure
ImageOptimizerOptions Members