OptimizeBuffer(RasterCodecs,IntPtr,long,ImageOptimizerOptions,ImageOptimizerProgress) Method

Summary

Optimizes a supported image format buffer using the passed optimization options.

Syntax
C#
VB
C++
  
Public Overloads Function OptimizeBuffer( _ 
   ByVal codecs As RasterCodecs, _ 
   ByVal buffer As IntPtr, _ 
   ByVal length As Long, _ 
   ByVal options As ImageOptimizerOptions, _ 
   ByVal progressCallback As ImageOptimizerProgress _ 
) As RasterNativeBuffer 
public: 
RasterNativeBuffer OptimizeBuffer(  
   RasterCodecs^ codecs, 
   IntPtr buffer, 
   int64 length, 
   ImageOptimizerOptions options, 
   ImageOptimizerProgress^ progressCallback 
)  

Parameters

codecs
The Leadtools.Codecs.RasterCodecs object used internally in the optimization operation.

buffer
The original image buffer in memory as System.IntPtr array. The image format in memory should be one of the following supported formats:

length
The size, in bytes, of the buffer parameter in memory.

options
The options used in the optimization process.

progressCallback
Optional callback function that provides information about the progress of the optimization process.

Return Value

A Leadtools.RasterNativeBuffer structure that contains the image optimized buffer in memory.

Remarks

For more information, refer to Image Optimization Using The ImageOptimizer Class.

Example

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

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageOptimization; 
 
public void TestPngImageOptimizer() 
{ 
   // Initialize the RasterCodecs class 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // The input and output location 
   string inputFileName = Path.Combine(LEAD_VARS.ImagesDir, "LittleGFlyingAlpha.png"); 
   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.PngQualityFactor = 4; 
 
   IntPtr bufferPtr; 
   int bufferSize = 0; 
   LoadFileIntoPointer(inputFileName, out bufferPtr, out bufferSize); 
 
   if (IntPtr.Zero != bufferPtr && bufferSize > 0) 
   { 
      RasterNativeBuffer optBuffer = optimizer.OptimizeBuffer(codecs, bufferPtr, bufferSize, options, null); 
 
      // Free orgBuffer.PointerBuffer, since it won't be needed anymore. 
      Marshal.FreeHGlobal(bufferPtr); 
 
      // 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)) 
      { 
         byte[] optArray = new byte[optBuffer.Length]; 
 
         Marshal.Copy(optBuffer.Data, optArray, 0, optArray.Length); 
         fs.Write(optArray, 0, optArray.Length); 
      } 
 
      // Free optBuffer.PointerBuffer, since it won't be needed anymore. 
      Marshal.FreeHGlobal(optBuffer.Data); 
 
      // 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. 
} 
 
// This method opens an image file and loads it into IntPtr. 
private void LoadFileIntoPointer(string fileName, out IntPtr ptr, out int size) 
{ 
   using (FileStream fs = File.OpenRead(fileName)) 
   { 
      // Allocate memory to load the file 
      size = (int)fs.Length; 
      ptr = Marshal.AllocHGlobal(size); 
 
      // Load in 32K chunks 
      const int bufferSize = 32 * 1024; 
      byte[] buffer = new byte[bufferSize]; 
 
      int bytesToRead; 
      int bytesLeft = (int)fs.Length; 
      IntPtr tempPtr = ptr;   // where we are 
      do 
      { 
         // read a chunk 
         bytesToRead = Math.Min(bufferSize, bytesLeft); 
         if (bytesToRead > 0) 
         { 
            fs.Read(buffer, 0, bytesToRead); 
 
            // copy into our buffer 
            Marshal.Copy(buffer, 0, tempPtr, bytesToRead); 
 
            // move the temp pointer 
            tempPtr = new IntPtr(tempPtr.ToInt64() + bytesToRead); 
 
            bytesLeft -= bytesToRead; 
         } 
      } 
      while (bytesToRead > 0); 
   } 
} 
 
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 TestPngImageOptimizer() 
   ' Initialize the RasterCodecs class 
   Dim Codecs As RasterCodecs = New RasterCodecs() 
 
   ' The input and output location 
   Dim inputFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "LittleGFlyingAlpha.png") 
   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.Distance = 20 
   options.Percent = 15 
   options.PngQualityFactor = 4 
 
   Dim bufferPtr As IntPtr 
   Dim bufferSize As Integer = 0 
   LoadFileIntoPointer(inputFileName, bufferPtr, bufferSize) 
 
   If (IntPtr.Zero <> bufferPtr AndAlso bufferSize > 0) Then 
      Dim optBuffer As RasterNativeBuffer = optimizer.OptimizeBuffer(Codecs, bufferPtr, bufferSize, options, Nothing) 
 
      ' Free orgBuffer.PointerBuffer, since it won't be needed anymore. 
      Marshal.FreeHGlobal(bufferPtr) 
 
      ' 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) 
 
         Dim optArray(CInt(optBuffer.Length)) As Byte 
 
         Marshal.Copy(optBuffer.Data, optArray, 0, optArray.Length) 
         fs.Write(optArray, 0, optArray.Length) 
      End Using 
 
      ' Free optBuffer.PointerBuffer, since it won't be needed anymore. 
      Marshal.FreeHGlobal(optBuffer.Data) 
 
      ' 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) 
      Console.WriteLine(message) 
   End If 
 
   'shutdown the RasterCodecs class. 
End Sub 
 
' This method opens an image file and loads it into IntPtr. 
Private Sub LoadFileIntoPointer(ByVal fileName As String, ByRef ptr As IntPtr, ByRef size As Integer) 
   Using fs As FileStream = File.OpenRead(fileName) 
      ' Allocate memory to load the file 
      size = CType(fs.Length, Integer) 
      ptr = Marshal.AllocHGlobal(size) 
 
      ' Load in 32K chunks 
      Const bufferSize As Integer = 32 * 1024 
      Dim buffer(bufferSize) As Byte 
 
      Dim bytesToRead As Integer 
 
      Dim bytesLeft As Integer = CType(fs.Length, Integer) 
      Dim tempPtr As IntPtr = ptr   ' where we are 
      Do 
         ' read a chunk 
         bytesToRead = Math.Min(bufferSize, bytesLeft) 
         If (bytesToRead > 0) Then 
            fs.Read(buffer, 0, bytesToRead) 
 
            ' copy into our buffer 
            Marshal.Copy(buffer, 0, tempPtr, bytesToRead) 
 
            ' move the temp pointer 
            tempPtr = New IntPtr(tempPtr.ToInt64() + bytesToRead) 
 
            bytesLeft -= bytesToRead 
         End If 
      Loop While (bytesToRead > 0) 
   End Using 
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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