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ReadThumbnail Method
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Leadtools.Codecs Namespace > RasterCodecs Class : ReadThumbnail Method




fileName
A String containing the name of the file from which the thumbnail image will be created.
options
Options for creating the thumbnail image.
pageNumber
1-based index of the page from which the thumbnail image should be created.
Creates a thumbnail from the specified image file.

Syntax

Visual Basic (Declaration) 
Public Function ReadThumbnail( _
   ByVal fileName As String, _
   ByVal options As CodecsThumbnailOptions, _
   ByVal pageNumber As Integer _
) As RasterImage
Visual Basic (Usage)Copy Code
Dim instance As RasterCodecs
Dim fileName As String
Dim options As CodecsThumbnailOptions
Dim pageNumber As Integer
Dim value As RasterImage
 
value = instance.ReadThumbnail(fileName, options, pageNumber)
C# 
public RasterImage ReadThumbnail( 
   string fileName,
   CodecsThumbnailOptions options,
   int pageNumber
)
Managed Extensions for C++ 
public: RasterImage ReadThumbnail( 
   string* fileName,
   CodecsThumbnailOptions options,
   int pageNumber
)
C++/CLI 
public:
RasterImage ReadThumbnail( 
   String^ fileName,
   CodecsThumbnailOptions options,
   int pageNumber
)

Parameters

fileName
A String containing the name of the file from which the thumbnail image will be created.
options
Options for creating the thumbnail image.
pageNumber
1-based index of the page from which the thumbnail image should be created.

Return Value

The RasterImage object that this method creates.

Example

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

         Dim srcFileName As String = "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Image1.cmp"

         ' Create a thumbnail with default options
         Dim options As CodecsThumbnailOptions = CodecsThumbnailOptions.Default
         options.LoadStamp = False
         Dim thumbnail As RasterImage = codecs.ReadThumbnail(srcFileName, options, 1)

         Console.WriteLine("Thumbnail with default option:")
         Console.WriteLine(" Size: {0} by {1} pixels. Bits/Pixel: {2}", thumbnail.Width, thumbnail.Height, thumbnail.BitsPerPixel)
         thumbnail.Dispose()

         ' Create a thumbnail with some options
         options.LoadStamp = False
         options.Width = 40
         options.Height = 80
         options.ForceSize = True
         options.MaintainAspectRatio = False
         options.BackColor = RasterColor.FromGdiPlusColor(Color.LightBlue)
         options.BitsPerPixel = 8
         thumbnail = codecs.ReadThumbnail(srcFileName, options, 1)

         Console.WriteLine("Thumbnail with set option (size: {0} by {1}, Bits/Pixel: {2}, ForeSize: {3}", options.Width, options.Height, options.BitsPerPixel, options.ForceSize)
         Console.WriteLine(" Size: {0} by {1} pixels. Bits/Pixel: {2}", thumbnail.Width, thumbnail.Height, thumbnail.BitsPerPixel)
         thumbnail.Dispose()

         codecs.Dispose()
         RasterCodecs.Shutdown()
      End Sub
C#Copy Code
RasterCodecs.ReadThumbnail 
      public void ReadThumbnailExample() 
      { 
         RasterCodecs.Startup(); 
         RasterCodecs codecs = new RasterCodecs(); 
 
         string srcFileName = @"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Image1.cmp"; 
 
         // Create a thumbnail with default options 
         CodecsThumbnailOptions options = CodecsThumbnailOptions.Default; 
         options.LoadStamp = false; 
         RasterImage thumbnail = codecs.ReadThumbnail(srcFileName, options, 1); 
 
         Console.WriteLine("Thumbnail with default option:"); 
         Console.WriteLine("  Size: {0} by {1} pixels. Bits/Pixel: {2}", thumbnail.Width, thumbnail.Height, thumbnail.BitsPerPixel); 
         thumbnail.Dispose(); 
 
         // Create a thumbnail with some options 
         options.LoadStamp = false; 
         options.Width = 40; 
         options.Height = 80; 
         options.ForceSize = true; 
         options.MaintainAspectRatio = false; 
         options.BackColor = RasterColor.FromGdiPlusColor(Color.LightBlue); 
         options.BitsPerPixel = 8; 
         thumbnail = codecs.ReadThumbnail(srcFileName, options, 1); 
 
         Console.WriteLine("Thumbnail with set option (size: {0} by {1}, Bits/Pixel: {2}, ForeSize: {3}", 
            options.Width, options.Height, options.BitsPerPixel, options.ForceSize); 
         Console.WriteLine("  Size: {0} by {1} pixels. Bits/Pixel: {2}", thumbnail.Width, thumbnail.Height, thumbnail.BitsPerPixel); 
         thumbnail.Dispose(); 
 
         codecs.Dispose(); 
         RasterCodecs.Shutdown(); 
      }

Remarks

This method will always return a thumbnail image. Depending on the options passed, this method might read the stamp stored inside EXIF, CMP, JFIF and FlashPix files and return that. To read the file stamp only, use ReadStamp.

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

See Also