Load(Stream,Int64,Int64) Method

public RasterImage Load( 
   Stream stream,
   long offset,
   long count
)

public RasterImage Load( 
   Stream stream,
   long offset,
   long count
)

 function Leadtools.Codecs.RasterCodecs.Load(Stream,Int64,Int64)( 
   stream ,
   offset ,
   count 
)

public:
RasterImage^ Load( 
   Stream^ stream,
   int64 offset,
   int64 count
)

'Declaration
 
Public Overloads Function Load( _
   ByVal stream As Stream, _
   ByVal offset As Long, _
   ByVal count As Long _
) As RasterImage

'Usage
 
Dim instance As RasterCodecs
Dim stream As Stream
Dim offset As Long
Dim count As Long
Dim value As RasterImage
 
value = instance.Load(stream, offset, count)

Parameters

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

Return Value

The Leadtools.RasterImage object that this method loads.

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. For these images, the load methods succeed, but LoadStatus will return an error code.

This method will load all the pages in a multipage file. The resulting image will have the same bits/pixel and color order value of the image as it was stored in the file.

LEADTOOLS will attempt to load corrupted files so you can see at least a portion of the image. For these images, the load methods succeed, but LoadStatus will return an error code.

Use the CodecsLoadOptions class to set up other load option parameters before calling this method.

Support for 12 and 16-bit grayscale, and 48 and 64-bit color 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.

The CodecsLoadOptions.AllPages property controls whether RasterCodecs will try to load all pages or just the first page if the image data contains multiple pages.

C#
Visual Basic

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.Drawing

Public Sub LoadStreamOffset1Example()
   Dim codecs As RasterCodecs = New RasterCodecs()

   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_LoadStreamOffset1.bmp")

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

   Dim ms As MemoryStream = New MemoryStream()

   ' Add some 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 with the offset
   Dim offset As Long = headerSize
   Dim count As Long = ms.Length - headerSize
   Dim image As RasterImage = codecs.Load(ms, offset, count)

   ' Save this image back to disk
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24)
   image.Dispose()

   ' Clean up
   codecs.Dispose()
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.ImageProcessing;
using Leadtools.ImageProcessing.Color;

public void LoadStreamOffset1Example()
{
   RasterCodecs codecs = new RasterCodecs();

   string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp");
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_LoadStreamOffset1.bmp");

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

   MemoryStream ms = new MemoryStream();

   // Add some 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;
   RasterImage image = codecs.Load(ms, offset, count);

   // Save this image back to disk
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24);
   image.Dispose();

   // Clean up
   codecs.Dispose();
}

static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

Target Platforms

Reference

RasterCodecs Class
RasterCodecs Members
Overload List
Loading and Saving Images
Loading and Saving Large Tiff Files
Speeding Up 1-Bit Documents
Fast File Info