FromHBitmap(IntPtr,IntPtr) Method

Visual Basic
C#
Objective-C
Java
C++

public static RasterImage FromHBitmap( 
   IntPtr hbitmap,
   IntPtr hpalette
)

'Declaration
 
Public Overloads Shared Function FromHBitmap( _
   ByVal hbitmap As IntPtr, _
   ByVal hpalette As IntPtr _
) As RasterImage

'Usage
 
Dim hbitmap As IntPtr
Dim hpalette As IntPtr
Dim value As RasterImage
 
value = RasterImageConverter.FromHBitmap(hbitmap, hpalette)

public:
static RasterImage^ FromHBitmap( 
   IntPtr hbitmap,
   IntPtr hpalette
)

Parameters

hbitmap: Handle to the Windows DDB.
hpalette: Handle to the Windows palette. This value can be IntPtr.Zero if the DDB is dependent on a device that is greater than 8 bits, or if the image will use the system palette.

Return Value

The newly create Leadtools.RasterImage object.

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

For more information refer to RasterImage and GDI/GDI+.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

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

<DllImport("gdi32")> _
Private Shared Function CreatePalette(ByVal lplgpl As LOGPALETTE256) As IntPtr
End Function
<DllImport("gdi32")> _
Private Shared Function DeleteObject(ByVal hObject As IntPtr) As Boolean
End Function

<StructLayout(LayoutKind.Sequential, Pack:=1)> _
Private Class LOGPALETTE256
   Public palVersion As Short
   Public palNumEntries As Short
   <MarshalAs(UnmanagedType.ByValArray, SizeConst:=1024)> _
   Public palPalEntry() As Byte
End Class


Public Sub FromHBitmapExample()
   Dim codecs As New RasterCodecs()

   ' load image as 8-bit
   Using image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"), 8, CodecsLoadByteOrder.Rgb, 1, 1)
      Dim hbitmap As IntPtr = IntPtr.Zero
      hbitmap = RasterImageConverter.ToHBitmap(image)

      Dim colors() As RasterColor

      Using btmp As New Bitmap(1, 1)
         Using g As Graphics = Graphics.FromImage(btmp)
            colors = RasterImagePainter.GetPaintColors(image, g)
         End Using
      End Using

      Dim hPalette As IntPtr = IntPtr.Zero
      If Not IsNothing(colors) AndAlso colors.Length <= 256 Then
         Dim log As New LOGPALETTE256()
         log.palVersion = &H300
         log.palNumEntries = CType(colors.Length, Short)
         ReDim log.palPalEntry(1023)

         Dim index As Integer = 0
         For i As Integer = 0 To colors.Length - 1
            log.palPalEntry(index + 0) = colors(i).R
            log.palPalEntry(index + 1) = colors(i).G
            log.palPalEntry(index + 2) = colors(i).B
            log.palPalEntry(index + 3) = 0
            index = index + 4
         Next

         hPalette = CreatePalette(log)
      End If

      Using destinationImage As RasterImage = RasterImageConverter.FromHBitmap(hbitmap, hPalette)
         codecs.Save(destinationImage, Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromHBitmap.bmp"), RasterImageFormat.Bmp, 0)
      End Using

      If hPalette <> IntPtr.Zero Then
         DeleteObject(hPalette)
      End If

      DeleteObject(hbitmap)
   End Using

   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.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

[DllImport("gdi32")]
private static extern IntPtr CreatePalette(LOGPALETTE256 lplgpl);
[DllImport("gdi32")]
private static extern bool DeleteObject(IntPtr hObject);
[StructLayout(LayoutKind.Sequential, Pack = 1)]
private class LOGPALETTE256
{
   public short palVersion;
   public short palNumEntries;
   [MarshalAs(UnmanagedType.ByValArray, SizeConst = 1024)]
   public byte[] palPalEntry;
}


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

   // load image as 8-bit
   using(RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir,"Image1.cmp"), 8, CodecsLoadByteOrder.Rgb, 1, 1))
   {
      IntPtr hbitmap = IntPtr.Zero;
      hbitmap = RasterImageConverter.ToHBitmap(image);

      RasterColor[] colors;

      using(Bitmap btmp = new Bitmap(1, 1))
      {
         using(Graphics g = Graphics.FromImage(btmp))
         {
            colors = RasterImagePainter.GetPaintColors(image, g);
         }
      }

      IntPtr hPalette = IntPtr.Zero;
      if(colors != null && colors.Length <= 256)
      {
         LOGPALETTE256 log = new LOGPALETTE256();
         log.palVersion = 0x300;
         log.palNumEntries = (short)colors.Length;
         log.palPalEntry = new byte[1024];

         int index = 0;
         for(int i = 0; i < colors.Length; i++)
         {
            log.palPalEntry[index++] = colors[i].R;
            log.palPalEntry[index++] = colors[i].G;
            log.palPalEntry[index++] = colors[i].B;
            log.palPalEntry[index++] = 0;
         }

         hPalette = CreatePalette(log);
      }

      using(RasterImage destinationImage = RasterImageConverter.FromHBitmap(hbitmap, hPalette))
      {
         codecs.Save(destinationImage,Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromHBitmap.bmp"), RasterImageFormat.Bmp, 0);
      }

      if(hPalette != IntPtr.Zero)
      {
         DeleteObject(hPalette);
      }

      DeleteObject(hbitmap);
   }

   codecs.Dispose();
}

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

Target Platforms

Reference

RasterImageConverter Class
RasterImageConverter Members
Overload List
ToHBitmap(RasterImage) Method
ChangeFromHBitmap(IntPtr,IntPtr) Method
ChangeToHBitmap(RasterImage) Method
RasterImage.FromDib
RasterImage.ToDib
RasterImage.ChangeFromDib
RasterImage.ChangeToDib