Extracts specific frames from the input stream, and saves them to a new JPEG 2000 file in a RasterNativeBuffer object. This file contains only the extracted frame headers/codestreams (not any obtained through the decompressing/recompressing process) so it saves processor time and memory. This method is available in the Document/Medical Toolkits.

Syntax

Visual Basic (Declaration)
Overloads Public Function ExtractFramesNativeMemory( _ ByVal stream As Stream, _ ByVal frames As List(Of Integer) _ ) As RasterNativeBuffer

Visual Basic (Usage)	Copy Code
`Dim instance As Jpeg2000Engine Dim stream As Stream Dim frames As List(Of Integer) Dim value As RasterNativeBuffer value = instance.ExtractFramesNativeMemory(stream, frames)`

C#
public RasterNativeBuffer ExtractFramesNativeMemory( Stream stream, List<int> frames )

Managed Extensions for C++
public: RasterNativeBuffer ExtractFramesNativeMemory( Stream* stream, List<int>* frames )

C++/CLI
public: RasterNativeBuffer ExtractFramesNativeMemory( Stream^ stream, List<int>^ frames )

Parameters

stream: A Stream containing the JPEG 2000 file data from which frames are being extracted.
frames: Frame indices. A list of integers specifying the indices of the frames to be extracted from the input stream. All indices should be 0-based.

Return Value

A RasterNativeBuffer object that contains a JPEG 2000 file with only the extracted frames.

Example

Visual Basic Copy Code

Visual Basic	Copy Code
Leadtools.Jpeg2000.Jpeg2000Engine.ExtractFramesNativeMemory(Stream) Private Function ExtractFramesNativeMemoryStreamExample(ByVal frames As List(Of Integer)) As RasterNativeBuffer Dim fs As FileStream = File.OpenRead("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\image1.jpx") Dim engine As New Jpeg2000Engine() Dim fileInfo As Jpeg2000FileInformation = engine.GetFileInformation(fs) For i As Integer = 0 To frames.Count - 1 If (frames(i) >= fileInfo.Frame.GetLength(0)) Then Return RasterNativeBuffer.Empty End If Next i Dim buffer As RasterNativeBuffer = engine.ExtractFramesNativeMemory(fs, frames) ' Clean up fs.Close() Return buffer End Function

Leadtools.Jpeg2000.Jpeg2000Engine.ExtractFramesNativeMemory(Stream)

      Private Function ExtractFramesNativeMemoryStreamExample(ByVal frames As List(Of Integer)) As RasterNativeBuffer

         Dim fs As FileStream = File.OpenRead("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\image1.jpx")



         Dim engine As New Jpeg2000Engine()

         Dim fileInfo As Jpeg2000FileInformation = engine.GetFileInformation(fs)



         For i As Integer = 0 To frames.Count - 1

            If (frames(i) >= fileInfo.Frame.GetLength(0)) Then

               Return RasterNativeBuffer.Empty

            End If

         Next i

         Dim buffer As RasterNativeBuffer = engine.ExtractFramesNativeMemory(fs, frames)



         '  Clean up

         fs.Close()

         Return buffer

      End Function

C# Copy Code

C#	Copy Code
Leadtools.Jpeg2000.Jpeg2000Engine.ExtractFramesNativeMemory(Stream) private RasterNativeBuffer ExtractFramesNativeMemoryStreamExample(List<int> frames) { FileStream fs = File.OpenRead(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\image1.jpx"); Jpeg2000Engine engine = new Jpeg2000Engine(); Jpeg2000FileInformation fileInfo = engine.GetFileInformation(fs); for (int i = 0; i < frames.Count; i++) if (frames[i] >= fileInfo.Frame.GetLength(0)) return RasterNativeBuffer.Empty; RasterNativeBuffer buffer = engine.ExtractFramesNativeMemory(fs, frames); // Clean up fs.Close(); return buffer; }

Leadtools.Jpeg2000.Jpeg2000Engine.ExtractFramesNativeMemory(Stream) 
      private RasterNativeBuffer ExtractFramesNativeMemoryStreamExample(List<int> frames) 
      { 
         FileStream fs = File.OpenRead(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\image1.jpx"); 
 
         Jpeg2000Engine engine = new Jpeg2000Engine(); 
         Jpeg2000FileInformation fileInfo = engine.GetFileInformation(fs); 
 
         for (int i = 0; i < frames.Count; i++) 
            if (frames[i] >= fileInfo.Frame.GetLength(0)) 
               return RasterNativeBuffer.Empty; 
         RasterNativeBuffer buffer = engine.ExtractFramesNativeMemory(fs, frames); 
         // Clean up 
         fs.Close(); 
         return buffer; 
      }

Remarks

. This method is very suitable for server applications where multiple clients request specific frames of a JPEG 2000 file.Instead of decompressing and then recompressing the frames this method copies only the needed frame data, saving the data to a new JPEG 2000 file.

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

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ExtractFramesNativeMemory(Stream,Generic List) Method
See Also Example