Extracts specific frames from the input stream, and saves them to a new JPEG 2000 file in a byte array. 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)
Public Overloads Function ExtractFramesMemory( _ ByVal stream As Stream, _ ByVal frames As List(Of Integer) _ ) As Byte()

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

C#
public byte[] ExtractFramesMemory( Stream stream, List<int> frames )

C++/CLI
public: array<byte>^ ExtractFramesMemory( Stream^ stream, List<int>^ frames )

Parameters

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

Return Value

A byte array that contains a JPEG 2000 file with extracted frames only.

Example

Visual Basic Copy Code

Visual Basic	Copy Code
Private Function ExtractFramesMemoryStreamExample(ByVal frames As List(Of Integer)) As Byte() Dim fs As FileStream = File.OpenRead(LeadtoolsExamples.Common.ImagesPath.Path + "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 Nothing End If Next i Dim buffer() As Byte = engine.ExtractFramesMemory(fs, frames) ' Clean up fs.Close() Return buffer End Function

Private Function ExtractFramesMemoryStreamExample(ByVal frames As List(Of Integer)) As Byte()

   Dim fs As FileStream = File.OpenRead(LeadtoolsExamples.Common.ImagesPath.Path + "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 Nothing

      End If

   Next i



   Dim buffer() As Byte = engine.ExtractFramesMemory(fs, frames)



   '  Clean up

   fs.Close()

   Return buffer

End Function

C# Copy Code

C#	Copy Code
private byte[] ExtractFramesMemoryStreamExample(List<int> frames) { FileStream fs = File.OpenRead(LeadtoolsExamples.Common.ImagesPath.Path + "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 null; byte [] buffer = engine.ExtractFramesMemory(fs, frames); // Clean up fs.Close(); return buffer; }

private byte[] ExtractFramesMemoryStreamExample(List<int> frames) 
{ 
   FileStream fs = File.OpenRead(LeadtoolsExamples.Common.ImagesPath.Path + "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 null; 
   byte [] buffer = engine.ExtractFramesMemory(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

Leadtools.Jpeg2000	Requires Document/Medical product license \| Send comments on this topic. \| Back to Introduction - All Topics \| Help Version 16.5.9.25
ExtractFramesMemory(Stream,Generic List) Method
See Also Example