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)

public RasterImage Load( 
   Stream stream,
   long offset,
   long count,
   int bitsPerPixel,
   CodecsLoadByteOrder order,
   int firstPage,
   int lastPage
)

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:

value	meaning
0	Keep the original file's pixel depth (Do not convert).
1 to 8	The specified bits per pixel in the resulting image.
12	12 bits per pixel in the resulting image.
16	16 bits per pixel in the resulting image.
24	24 bits per pixel in the resulting image.
32	32 bits per pixel in the resulting image.
48	48 bits per pixel in the resulting image.
64	64 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.

Value	Meaning
CodecsLoadByteOrder.Rgb	Red, green, and blue color order in memory
CodecsLoadByteOrder.Bgr	Blue, green, and red color order in memory
CodecsLoadByteOrder.Gray	12 or 16-bit grayscale image. 12 and 16-bit grayscale images are only supported in the Document/Medical Imaging editions.
CodecsLoadByteOrder.RgbOrGray	Load 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.BgrOrGray	Load 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.Romm	ROMM order. ROMM only supports 24 and 48-bit images
CodecsLoadByteOrder.BgrOrGrayOrRomm	Load 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

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

Visual Basic

Copy 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();  }

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.

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

Reference