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Date Posted: 09:41:04 05/16/00 Tue
Author: Jöerg
Subject: Re: Acquire with ShowUI=true
In reply to: Michel 's message, "Re: Acquire with ShowUI=true" on 07:33:36 05/16/00 Tue

Hi Michel,

sorry, but where do I get the property "ImageFormat" without a Graphic class?

case Graphic.ImageFormat of
ifBlackWhite: {do something}
end;

Do I need to create a TDibGraphic first, use case statement and create a TTiffGraphic (i.e.) second? Or can I get ImageFormat from DibHandle?

Thanks and best regards
Joerg

>
> Hi Joerg,
>
> In your code, the problem is that you are creating
> your Graphic as a TDibGraphic, so you cannot typecast
> it to a TTiffGraphic or TJpegGraphic. Instead, create
> your Graphic object in the case statement itself:
>
> case Graphic.ImageFormat of
> ifBlackWhite:
> begin
> Graphic := TTiffGraphic.Create;
> Graphic.AssignFromDibHandle(DibHandle);
> Graphic.XDotsPerInch := XDpi;
> Graphic.YDotsPerInch := YDpi;
> Graphic.Compression := tcGroup4;
> Graphic.SaveToFile('c:\temp\test.tif');
> end;
> ifTrueColor:
> begin
> Graphic := TJpegGraphic.Create;
> Graphic.AssignFromDibHandle(DibHandle);
> Graphic.XDotsPerInch := XDpi;
> Graphic.YDotsPerInch := YDpi;
> Graphic.SaveToFile('c:\temp\test.jpg');
> end;
> end; { case }
>
> You should also add a default in your case statement
> to handle other image formats.
>
> Best regards,
>
> Michel
>
> > Hello Michel,
> >
> > how can I get information about ImageFormat and
> > XYResolution with ShowUI=true? I need it to select
> the
> > best image filetype and compression.
> >
> > Example:
> > If user acquires a bw image, my app shall save it
> > automatically as tif fax g4, if he scans truecolor,
> my
> > app shall save it as jpeg. Please have a look at the
> > following source. Can I do so or what goes wrong?
> >
> > procedure TXImageFrame.Acquire(const DibHandle:
> > THandle; const XDpi,
> > YDpi: Word; const CallBackData: Integer);
> > var Graphic: TDibGraphic;
> > begin
> > Graphic := TDibGraphic.Create;
> > try
> > Graphic.AssignFromDibHandle(DibHandle);
> > Graphic.XDotsPerInch := XDpi;
> > Graphic.YDotsPerInch := YDpi;
> > case Graphic.ImageFormat of
> > ifBlackWhite: with TTiffGraphic(Graphic) do
> begin
> > Compression := tcGroup4;
> > SaveToFile('c:\temp\test.tif');
> > end;
> > ifTrueColor:
> > TJpegGraphic(Graphic).SaveToFile('c:\temp\test.jpg');
> > end;
> > finally
> > Graphic.Free;
> > end;
> > end;
> >
> > Thank you very much and regards from germany
> > Joerg

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