FromEmf(IntPtr,Int32,Int32) Method

public static RasterImage FromEmf( 
   IntPtr hemf,
   int width,
   int height
)

'Declaration
 

Public Overloads Shared Function FromEmf( _
   ByVal hemf As IntPtr, _
   ByVal width As Integer, _
   ByVal height As Integer _
) As RasterImage

'Usage
 

Dim hemf As IntPtr
Dim width As Integer
Dim height As Integer
Dim value As RasterImage
 
value = RasterImageConverter.FromEmf(hemf, width, height)

public:
static RasterImage^ FromEmf( 
   IntPtr hemf,
   int width,
   int height
) 

Parameters

hemf

Handle to the EMF to be converted.

width

Amount by which to scale the enhanced metafiles original width.

height

Amount by which to scale the enhanced metafiles original height.

Return Value

Some metafiles do not have a background color, and hence, when the metafile is used to create a Leadtools.RasterImage object, the area not covered by the metafile objects will contain the default image background color (black). To create a raster image from a metafile like this with a specific background color, use FromEmf(hemf, width, height, backColor).

When this method is completed, there are two copies of the drawing in memory: the new Leadtools.RasterImage object and the original EMF. Freeing one will not affect the other.

The enhanced metafile can be loaded at the original dimension or scaled by using the width and height parameters.

If width == 0 and height == 0 - the enhanced metafile is loaded at the size present in the file.

If width == 0 and height > 0 - the enhanced metafile is stretched so that it has the height height (preserving the aspect ratio).

If width > 0 and height == 0 - the enhanced metafile is stretched so that it has the width width (preserving the aspect ratio).

If width > 0 and height > 0 - the enhanced metafile is stretched so that it has the width width and height height (the aspect ratio is ignored).

This method does not support signed images.

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

This example loads a Leadtools.RasterImage, converts it to a EMF, then converts the EMF back to a Leadtools.RasterImage.

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

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

<DllImport("Gdi32", CharSet:=CharSet.Auto)> _
Private Shared Function DeleteEnhMetaFile(ByVal hemf As IntPtr) As Integer
End Function
<TestMethod()> _
Public Sub FromEmfExample()
   Dim codecs As New RasterCodecs()

   Dim hemf As IntPtr

   ' Load an image
   Using image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"), 24, CodecsLoadByteOrder.BgrOrGray, 1, 1)
      ' Convert it to EMF
      hemf = RasterImageConverter.ToEmf(image)

      ' Note, since we converted to an EMF we have two copies of the image in memory and "image" is still usable
   End Using

   ' Convert the EMF back to a RasterImage preserving the size
   Using image As RasterImage = RasterImageConverter.FromEmf(hemf, 0, 0)
      ' Not since we converted from the EMF, we need to delete it ourselves
      DeleteEnhMetaFile(hemf)

      ' Save it to disk
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromEmf.bmp"), RasterImageFormat.Bmp, 24)
   End Using

   ' Clean up
   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", CharSet = CharSet.Auto)]
private static extern int DeleteEnhMetaFile(IntPtr hemf);
[TestMethod]
public void FromEmfExample()
{
   RasterCodecs codecs = new RasterCodecs();

   IntPtr hemf;

   // Load an image
   using(RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"), 24, CodecsLoadByteOrder.BgrOrGray, 1, 1))
   {
      // Convert it to EMF
      hemf = RasterImageConverter.ToEmf(image);

      // Note, since we converted to an EMF we have two copies of the image in memory and "image" is still usable
   }

   // Convert the EMF back to a RasterImage preserving the size
   using(RasterImage image = RasterImageConverter.FromEmf(hemf, 0, 0))
   {
      // Not since we converted from the EMF, we need to delete it ourselves
      DeleteEnhMetaFile(hemf);

      // Save it to disk
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromEmf.bmp"), RasterImageFormat.Bmp, 24);
   }

   // Clean up
   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
FromEmf(hemf, width, height, backColor)
ChangeFromEmf(IntPtr,Int32,Int32) Method
ChangeFromWmf(IntPtr,Int32,Int32) Method
FromWmf
ChangeToEmf Method
ChangeToWmf Method
ToEmf
ToWmf