Draw PNG files from EMF files faster

are you generating one image file or multiple image files (i am assuming multiple images)
in case of multiple images you can use threads to generate your images and it will expedite your process of images generation as each independent thread will be generating one image
I dont think there is much there to improve the performance as i think its a standard piece of code what you have shown in the query above

>>'  We want a high quality .png file.
>>'  Let's quadruple the height and width.

Larger size does not equate to higher quality

Please do a performance test and do this conversion without increasing the image size.

I generate each image file in sequence so I don't have the option of using multiple threads.

If the images are not made larger before conversion, then when the png is resized larger, it becomes blurry.

To clarify, there are 107 EMF files. The process (with N = 107 in my example) goes

For i = 1 to N
   Run some code
   Create EMF file
   Convert EMF file for 3rd party software that won't use EMFs
Next  

aikimark, you were absolutely right. If I don't do the 4x4 increase, the time goes from 54 seconds down to 3 seconds. The one drawback is I now have an image that is fuzzy when it is resized larger.

> The process (with N = 107 in my example) goes
>Create EMF file

Do you have  control on the Create EMF Files process?

Yes. They are graphs that are also created in the same program.

Can you not change size of those?

But they are based on the incoming numbers, so each graph is different.

I'm not sure I understand what you mean by changing the size.

Can you show the code that's generating these EMF files?

I like where you're going with this CC.  In addition to the source program, we might also consider preprocessing the EMF file, adjusting the size parameters before bringing it into the conversion process.

There is a lot of code for creating the individual lines and symbols so I've just left the shell to give you an idea.

Public Function GetMetaFile(ByVal FileName As String) As Metafile
        Dim G As Graphics = MetaDisplayFrm.CreateGraphics()
        Dim ipHdc As IntPtr = G.GetHdc()
        Dim MF As Metafile
        MF = New Metafile(FileName, ipHdc)
        G.ReleaseHdc(ipHdc)
        G.Dispose()
        Return MF
    End Function

        Using MF As Metafile = GetMetaFile(H.MFName)
            If IsNothing(MF) Then
                Exit Sub
            End If
            Using G As Graphics = Graphics.FromImage(MF)
                G.SmoothingMode = SmoothingMode.AntiAlias
                G.TextRenderingHint = GloTextRenderingHint

                HistoReadBinParms(H.HP)
                AxisOppositesInit(H.Axis(_Ax.T), H.Axis(_Ax.L))
                AxisOppositesInit(H.Axis(_Ax.B), H.Axis(_Ax.R))
                HistoSetAxisBoundaries(_Ax.T, H.Axis(_Ax.T))
                HistoSetAxisBoundaries(_Ax.B, H.Axis(_Ax.B))
                AxisBoundariesInit(_Ax.L, H.Axis(_Ax.L))
                AxisBoundariesInit(_Ax.R, H.Axis(_Ax.R))
.
.
.
G.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias
            G.DrawLine(MyPen, PX0, PY0, PX1, PY1)
(many more lines and symbols in similar manner)
.
.
.
            End Using
        End Using

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Hmm. Looks like a lot of drawing is going on in the EMF file. One of the constructors for Metafile class takes a rectangle as bounds. Try that

http://msdn.microsoft.com/en-us/library/2ea632z6.aspx

I can't get the graph to draw properly with the rectangle. I think the difficulty might be that I don't know what the coordinates of the rectangle should be until after the drawing takes place.

You may have to live with it then? Are you using .NET 4? Then you can use Parallels or Tasks or else you can use threading.

We are still in 3.5. Thank you for your input.

If we can't find you some decent performance, you might need to look at some other conversion routes.

http://downloadnew.org/home-hobby/other/image-convert-11228.html
http://www.ivanview.com/converter/emf-batch-converter.html
http://www.yankeedownload.com/software/abc-amber-svg-converter-imblq.html
http://www.yankeedownload.com/software/able-batch-converter-inlle.html
http://help.imageconverterplus.com/how-to-convert/emf_png.html

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Companion Software had a couple of (potentially) useful pages:
http://www.companionsoftware.com/Support/Resources/OtherHelpfulWebsites.aspx#Graphics%20Conversion%20Software

http://www.companionsoftware.com/Support/Resources/OtherHelpfulWebsites.aspx