Public Function ChangeToDib( _
   ByVal type As RasterConvertToDibType _
) As IntPtr

Visual Basic (Usage)	Copy Code
Dim instance As RasterImage Dim type As RasterConvertToDibType Dim value As IntPtr   value = instance.ChangeToDib(type)

public IntPtr ChangeToDib( 
   RasterConvertToDibType type
)

public:
IntPtr ChangeToDib( 
   RasterConvertToDibType type
) 

Parameters

type

Type of DIB to create. Possible values are:

Value	Meaning
RasterConvertToDibType.BitmapInfoHeader	DIB that uses a BITMAPINFOHEADER
RasterConvertToDibType.BitmapV4Header	DIB that uses a BITMAPV4HEADER. (Introduced in Windows 95 and Windows NT 4.0)
RasterConvertToDibType.BitmapV5Header	DIB that uses a BITMAPV5HEADER (Introduced in Windows 2000 and Windows 98)

Return Value

This example loads a RasterImage, changes it to a V5 DIB and writes out the DIB as a bitmap file.

Visual Basic

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<DllImport("Kernel32", CharSet:=CharSet.Auto)> _ Shared Function GlobalSize(ByVal hMem As IntPtr) As IntPtr End Function <DllImport("Kernel32", CharSet:=CharSet.Auto)> _ Shared Function GlobalLock(ByVal hMem As IntPtr) As IntPtr End Function <DllImport("Kernel32", CharSet:=CharSet.Auto)> _ Shared Function GlobalUnlock(ByVal hMem As IntPtr) As Integer End Function <DllImport("Kernel32", CharSet:=CharSet.Auto)> _ Shared Function GlobalFree(ByVal hMem As IntPtr) As IntPtr End Function <StructLayout(LayoutKind.Sequential, Pack:=1)> _ Class BITMAPFILEHEADER    Public bfType As UShort    Public bfSize As UInteger    Public bfReserved1 As UShort    Public bfReserved2 As UShort    Public bfOffBits As UInteger End Class <StructLayout(LayoutKind.Sequential, Pack:=1)> _ Class BITMAPINFOHEADER    Public biSize As UInteger    Public biWidth As Integer    Public biHeight As Integer    Public biPlanes As UShort    Public biBitCount As UShort    Public biCompression As UInteger    Public biSizeImage As UInteger    Public biXPelsPerMeter As Integer    Public biYPelsPerMeter As Integer    Public biClrUsed As UInteger    Public biClrImportant As UInteger End Class <StructLayout(LayoutKind.Sequential, Pack:=1)> _ Class RGBQUAD    Public rgbBlue As Byte    Public rgbGreen As Byte    Public rgbRed As Byte    Public rgbReserved As Byte End Class Public Sub ChangeToDibExample()    RasterCodecs.Startup()    Dim codecs As New RasterCodecs()    ' Load an image    Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp", 24, CodecsLoadByteOrder.BgrOrGray, 1, 1)    ' Change to DIB    Dim hdib As IntPtr = image.ChangeToDib(RasterConvertToDibType.BitmapInfoHeader)    ' Dispose the image since it is unusable now    image.Dispose()    ' Clean up    codecs.Dispose()    RasterCodecs.Shutdown()    ' Save this DIB to disk as a BMP file    Dim dibSize As Integer = GlobalSize(hdib).ToInt32()    Dim bmfh As New BITMAPFILEHEADER()    bmfh.bfType = &H4D42 ' "BM"    bmfh.bfSize = CUInt(Marshal.SizeOf(GetType(BITMAPFILEHEADER)) + dibSize)    bmfh.bfReserved1 = 0    bmfh.bfReserved2 = 0    Dim pdib As IntPtr = GlobalLock(hdib)    Dim bmih As New BITMAPINFOHEADER()    Marshal.PtrToStructure(pdib, bmih)    bmfh.bfOffBits = CUInt(Marshal.SizeOf(GetType(BITMAPFILEHEADER)) + bmih.biSize + bmih.biClrUsed * Marshal.SizeOf(GetType(RGBQUAD)))    Using fs As FileStream = File.Create(LeadtoolsExamples.Common.ImagesPath.Path + "Image1_ToDib.bmp")       Dim writer As New BinaryWriter(fs)       writer.Write(bmfh.bfType)       writer.Write(bmfh.bfSize)       writer.Write(bmfh.bfReserved1)       writer.Write(bmfh.bfReserved2)       writer.Write(bmfh.bfOffBits)       Dim buffer(1023) As Byte       Dim offset As Integer = 0       While (offset < dibSize)          Dim bytes As Integer = Math.Min(dibSize - offset, buffer.Length)          Marshal.Copy(New IntPtr(pdib.ToInt64() + offset), buffer, 0, bytes)          fs.Write(buffer, 0, bytes)          offset = offset + bytes       End While    End Using    GlobalUnlock(hdib)    GlobalFree(hdib) End Sub

C#

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[DllImport("Kernel32", CharSet = CharSet.Auto)]  static extern IntPtr GlobalSize(IntPtr hMem);  [DllImport("Kernel32", CharSet = CharSet.Auto)]  static extern IntPtr GlobalLock(IntPtr hMem);    [DllImport("Kernel32", CharSet = CharSet.Auto)]  static extern int GlobalUnlock(IntPtr hMem);    [DllImport("Kernel32", CharSet = CharSet.Auto)]  static extern IntPtr GlobalFree(IntPtr hMem);    [StructLayout(LayoutKind.Sequential, Pack = 1)]  class BITMAPFILEHEADER  {     public ushort bfType;     public uint bfSize;     public ushort bfReserved1;     public ushort bfReserved2;     public uint bfOffBits;  }    [StructLayout(LayoutKind.Sequential, Pack = 1)]  class BITMAPINFOHEADER  {     public uint biSize;     public int biWidth;     public int biHeight;     public ushort biPlanes;     public ushort biBitCount;     public uint biCompression;     public uint biSizeImage;     public int biXPelsPerMeter;     public int biYPelsPerMeter;     public uint biClrUsed;     public uint biClrImportant;  }    [StructLayout(LayoutKind.Sequential, Pack = 1)]  class RGBQUAD  {     public byte rgbBlue;     public byte rgbGreen;     public byte rgbRed;     public byte rgbReserved;  }      public void ChangeToDibExample()  {     RasterCodecs.Startup();     RasterCodecs codecs = new RasterCodecs();       // Load an image     RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp", 24, CodecsLoadByteOrder.BgrOrGray, 1, 1);       // Change to DIB     IntPtr hdib = image.ChangeToDib(RasterConvertToDibType.BitmapInfoHeader);       // Dispose the image since it is unusable now     image.Dispose();       // Clean up     codecs.Dispose();     RasterCodecs.Shutdown();       // Save this DIB to disk as a BMP file       int dibSize = GlobalSize(hdib).ToInt32();       BITMAPFILEHEADER bmfh = new BITMAPFILEHEADER();     bmfh.bfType = 0x4d42; // "BM"     bmfh.bfSize = (uint)(Marshal.SizeOf(typeof(BITMAPFILEHEADER)) + dibSize);     bmfh.bfReserved1 = 0;     bmfh.bfReserved2 = 0;       IntPtr pdib = GlobalLock(hdib);       BITMAPINFOHEADER bmih = new BITMAPINFOHEADER();     Marshal.PtrToStructure(pdib, bmih);       bmfh.bfOffBits = (uint)(Marshal.SizeOf(typeof(BITMAPFILEHEADER)) + bmih.biSize + bmih.biClrUsed * Marshal.SizeOf(typeof(RGBQUAD)));       using(FileStream fs = File.Create(LeadtoolsExamples.Common.ImagesPath.Path + "Image1_ToDib.bmp"))     {        BinaryWriter writer = new BinaryWriter(fs);        writer.Write(bmfh.bfType);        writer.Write(bmfh.bfSize);        writer.Write(bmfh.bfReserved1);        writer.Write(bmfh.bfReserved2);        writer.Write(bmfh.bfOffBits);          byte[] buffer = new byte[1024];        int offset = 0;        while(offset < dibSize)        {           int bytes = Math.Min(dibSize - offset, buffer.Length);           Marshal.Copy(new IntPtr(pdib.ToInt64() + offset), buffer, 0, bytes);           fs.Write(buffer, 0, bytes);             offset += bytes;        }     }       GlobalUnlock(hdib);     GlobalFree(hdib);  }

A DIB consists of one of the following:

• a BITMAPFILEHEADER,
• a BITMAPV4HEADER (introduced in Windows 95 and Windows NT 4.0),
• or a BITMAPV5HEADER (introduced in Windows 2000 and Windows 98),

followed by a color table and then the bitmap data. The resulting DIB type is determined by the value of the type parameter.

The orientation of the image and color order will depend on how the image was loaded into the RasterImage.

When you no longer need the DIB, you can free it using the Windows GlobalFree function.

This method does not support signed data images. It will throw an exception of type RasterException with code value RasterExceptionCode.SignedDataNotSupported if this RasterImage has a signed data image.

For more information on DDBs and DIBs, refer to Using DIBs, DDBs, and the Clipboard.

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

Reference