OptimizeBuffer(RasterCodecs,IntPtr,Int64,ImageOptimizerOptions,ImageOptimizerProgress) Method

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

Syntax

C#
Visual Basic
Objective-C
Java
C++

public RasterNativeBuffer OptimizeBuffer( 
   RasterCodecs codecs,
   IntPtr buffer,
   long length,
   ImageOptimizerOptions options,
   ImageOptimizerProgress progressCallback
)

'Declaration
 
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

'Usage
 
Dim instance As ImageOptimizer
Dim codecs As RasterCodecs
Dim buffer As IntPtr
Dim length As Long
Dim options As ImageOptimizerOptions
Dim progressCallback As ImageOptimizerProgress
Dim value As RasterNativeBuffer
 
value = instance.OptimizeBuffer(codecs, buffer, length, options, progressCallback)

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:

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).
RasterImageFormat.Gif, Bits per pixel: 1, 2, 3, 4, 5, 6, 7, and 8.
RasterImageFormat.Png, Bits per pixel: 1, 4, 8, 24, 32, 48, and 64.
RasterImageFormat.Bmp, Bits per pixel: 1, 4, 8, 16, 24, and 32.
RasterImageFormat.BmpRle, Bits per pixel: 4, and 8.

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

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageOptimization
Imports Leadtools.Support.Examples

<TestMethod()> _
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

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageOptimization;

[TestMethod]
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";
}

Requirements

Target Platforms

Reference

ImageOptimizer Class
ImageOptimizer Members
Overload List