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Load(Stream,Int64,Int64) Method
See Also  Example
Leadtools.Windows.Controls Namespace > RasterImageViewer Class > Load Method : Load(Stream,Int64,Int64) Method



stream
A Stream containing the image data to load.
offset
Offset from the beginning of the stream at which loading should begin.
count
Total size of the image file data.
stream
A Stream containing the image data to load.
offset
Offset from the beginning of the stream at which loading should begin.
count
Total size of the image file data.
Loads an image file, letting you specify the location of the image data within the stream.

Syntax

Visual Basic (Declaration) 
Overloads Public Sub Load( _
   ByVal stream As Stream, _
   ByVal offset As Long, _
   ByVal count As Long _
) 
Visual Basic (Usage)Copy Code
Dim instance As RasterImageViewer
Dim stream As Stream
Dim offset As Long
Dim count As Long
 
instance.Load(stream, offset, count)
C# 
public void Load( 
   Stream stream,
   long offset,
   long count
)
C++/CLI 
public:
void Load( 
   Stream^ stream,
   long offset,
   long count
) 

Parameters

stream
A Stream containing the image data to load.
offset
Offset from the beginning of the stream at which loading should begin.
count
Total size of the image file data.

Example

This example will load an image located in an offset into a stream.

Visual BasicCopy Code
Public Sub RasterImageViewer_Load3(ByVal viewer As RasterImageViewer)
    Dim srcFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp"
    Dim destFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_LoadStreamOffset1.bmp"

    ' Create a memory stream, add a custom header and then copy the content of the file
    ' into this stream. After that, load the image from the stream using the offset.

    Dim ms As MemoryStream = New MemoryStream()

    ' Add a custom header to the stream (4 bytes)
    Dim headerSize As Integer = 4
    Dim i As Integer = 0
    Do While i < headerSize
        ms.WriteByte(0)
        i += 1
    Loop

    ' Now append the file into this stream
    Dim fs As FileStream = File.OpenRead(srcFileName)

    Const bufferSize As Integer = 1024
    Dim buffer As Byte() = New Byte(bufferSize - 1) {}
    Dim bytesRead As Integer
    Do
        bytesRead = fs.Read(buffer, 0, bufferSize)
        If bytesRead > 0 Then
            ms.Write(buffer, 0, bytesRead)
        End If
    Loop While bytesRead > 0

    fs.Close()

    ' Reset the memory stream position to the beginning
    ms.Position = 0

    ' Now load the image using the offset
    Dim offset As Long = headerSize
    Dim count As Long = ms.Length - headerSize
    viewer.Load(ms, offset, count)

    ' Save this image back to disk
    viewer.Save(destFileName, RasterImageFormat.Bmp, 24, 0)
End Sub
C#Copy Code
public void RasterImageViewer_Load3(RasterImageViewer viewer) 

   string srcFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp"; 
   string destFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_LoadStreamOffset1.bmp"; 
 
   // Create a memory stream, add a custom header and then copy the content of the file 
   // into this stream.  After that, load the image from the stream using the given offset. 
 
   MemoryStream ms = new MemoryStream(); 
 
   // Add a custom header to the stream (4 bytes) 
   int headerSize = 4; 
   for (int i = 0; i < headerSize; i++) 
      ms.WriteByte(0); 
 
   // Now append the file into this stream 
   FileStream fs = File.OpenRead(srcFileName); 
 
   const int bufferSize = 1024; 
   byte[] buffer = new byte[bufferSize]; 
   int bytesRead; 
   do 
   { 
      bytesRead = fs.Read(buffer, 0, bufferSize); 
      if (bytesRead > 0) 
         ms.Write(buffer, 0, bytesRead); 
   } 
   while (bytesRead > 0); 
 
   fs.Close(); 
 
   // Reset the memory stream position to the beginning 
   ms.Position = 0; 
 
   // Now load the image with the offset 
   long offset = headerSize; 
   long count = ms.Length - headerSize; 
   viewer.Load(ms, offset, count); 
 
   // Save this image back to disk 
   viewer.Save(destFileName, RasterImageFormat.Bmp, 24, 0); 
}

Remarks

This method can be used to load an image file that is embedded in another stream.

The location of the image is specified as shown in the following simple illustration:

LEADTOOLS will attempt to load corrupted files, so you can see at least a portion of the image.

Support for 12- and 16-bit grayscale images is only available in the Document/Medical Imaging editions.

For supported formats, refer to Summary of All Supported Image File Formats.

LEADTOOLS loads all PDF files as Raster PDF uncompressed RasterImageFormat.RasPdf, regardless of the compression and color space used when saving the file.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Vista, and Windows Server 2003 family

See Also