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Load(Stream,Int64,Int64,Int32,CodecsLoadByteOrder,Int32,Int32) Method
See Also  Example
Leadtools.Codecs Namespace > RasterCodecs Class > Load Method : Load(Stream,Int64,Int64,Int32,CodecsLoadByteOrder,Int32,Int32) Method



stream
A 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.
bitsPerPixel

Resulting image pixel depth. Valid values are:

valuemeaning
0Keep the original file's pixel depth (Do not convert).
1 to 8The specified bits per pixel in the resulting image.
1212 bits per pixel in the resulting image.
1616 bits per pixel in the resulting image.
2424 bits per pixel in the resulting image.
3232 bits per pixel in the resulting image.
4848 bits per pixel in the resulting image.
6464 bits per pixel in the resulting image.

order

Color order for 16-, 24-, 32-, 48-, and 64-bit images. If the resulting image is less than 16 bits per pixel, this will have no effect since palletized images have no order. The following are valid values.

ValueMeaning
CodecsLoadByteOrder.RgbRed, green, and blue color order in memory
CodecsLoadByteOrder.BgrBlue, green, and red color order in memory
CodecsLoadByteOrder.Gray12 or 16-bit grayscale image. 12 and 16-bit grayscale images are only supported in the Document/Medical Imaging editions.
CodecsLoadByteOrder.RgbOrGrayLoad the image as red, green, blue OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.BgrOrGrayLoad the image as blue, green, red OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.RommROMM order. ROMM only supports 24 and 48-bit images
CodecsLoadByteOrder.BgrOrGrayOrRommLoad the image as red, green, blue OR as a 12 or 16-bit grayscale image OR as ROMM. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions only. ROMM only supports 24 and 48-bit color images.

firstPage
1-based index of the first page to load.
lastPage
The 1-based index of the last page to load. Must be greater than or equal to firstPage. You can pass -1 to load from firstPage to the last page in the stream.
Loads an image file, letting you specify the location of the image data within the stream and the options to use when loading.

Syntax

Visual Basic (Declaration) 
Public Overloads Function Load( _
   ByVal stream As Stream, _
   ByVal offset As Long, _
   ByVal count As Long, _
   ByVal bitsPerPixel As Integer, _
   ByVal order As CodecsLoadByteOrder, _
   ByVal firstPage As Integer, _
   ByVal lastPage As Integer _
) As RasterImage
Visual Basic (Usage)Copy Code
Dim instance As RasterCodecs
Dim stream As Stream
Dim offset As Long
Dim count As Long
Dim bitsPerPixel As Integer
Dim order As CodecsLoadByteOrder
Dim firstPage As Integer
Dim lastPage As Integer
Dim value As RasterImage
 
value = instance.Load(stream, offset, count, bitsPerPixel, order, firstPage, lastPage)
C# 
public RasterImage Load( 
   Stream stream,
   long offset,
   long count,
   int bitsPerPixel,
   CodecsLoadByteOrder order,
   int firstPage,
   int lastPage
)
C++/CLI 
public:
RasterImage Load( 
   Stream^ stream,
   long offset,
   long count,
   int bitsPerPixel,
   CodecsLoadByteOrder order,
   int firstPage,
   int lastPage
) 

Parameters

stream
A 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.
bitsPerPixel

Resulting image pixel depth. Valid values are:

valuemeaning
0Keep the original file's pixel depth (Do not convert).
1 to 8The specified bits per pixel in the resulting image.
1212 bits per pixel in the resulting image.
1616 bits per pixel in the resulting image.
2424 bits per pixel in the resulting image.
3232 bits per pixel in the resulting image.
4848 bits per pixel in the resulting image.
6464 bits per pixel in the resulting image.

order

Color order for 16-, 24-, 32-, 48-, and 64-bit images. If the resulting image is less than 16 bits per pixel, this will have no effect since palletized images have no order. The following are valid values.

ValueMeaning
CodecsLoadByteOrder.RgbRed, green, and blue color order in memory
CodecsLoadByteOrder.BgrBlue, green, and red color order in memory
CodecsLoadByteOrder.Gray12 or 16-bit grayscale image. 12 and 16-bit grayscale images are only supported in the Document/Medical Imaging editions.
CodecsLoadByteOrder.RgbOrGrayLoad the image as red, green, blue OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.BgrOrGrayLoad the image as blue, green, red OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.RommROMM order. ROMM only supports 24 and 48-bit images
CodecsLoadByteOrder.BgrOrGrayOrRommLoad the image as red, green, blue OR as a 12 or 16-bit grayscale image OR as ROMM. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions only. ROMM only supports 24 and 48-bit color images.

firstPage
1-based index of the first page to load.
lastPage
The 1-based index of the last page to load. Must be greater than or equal to firstPage. You can pass -1 to load from firstPage to the last page in the stream.

Return Value

The RasterImage object that this method loads.

Example

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

Visual BasicCopy Code
Public Sub LoadStreamOffset2Example()
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()

   Dim srcFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Eye.gif"
   Dim destFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_LoadStreamOffset2.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 second page in the image using the offset
   Dim offset As Long = headerSize
   Dim count As Long = ms.Length - headerSize
   Dim image As RasterImage = codecs.Load(ms, offset, count, 0, CodecsLoadByteOrder.BgrOrGray, 2, 2)

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

   ' Clean up
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void LoadStreamOffset2Example() 

   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   string srcFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Eye.gif"; 
   string destFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1_LoadStreamOffset2.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 
 
   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 second page in the image using the offset 
   long offset = headerSize; 
   long count = ms.Length - headerSize; 
   RasterImage image = codecs.Load(ms, offset, count, 0, CodecsLoadByteOrder.BgrOrGray, 2, 2); 
 
   // Save this image back to disk 
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); 
   image.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

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. 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 options parameters before calling this method.

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 Server 2003 family, Windows Server 2008 family

See Also