Saving a tchart's image to a Jpeg file
lazarus / 39-Graphics

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Pi · 2014-07-08 18:17

Is there a simple way to save a Tchart's image to a Jpeg file?

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wp · 2014-07-08 18:26

Code: [Select]  Chart1.SaveToFile(TJPEGImage, 'MyImage.jpg');

See also the demo project in components/tachart/demo/save of your
lazarus installation, or
http://wiki.lazarus.freepascal.org/TAChart_Demos#save

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Pi · 2014-07-08 18:41

Quote from: wp on July 08, 2014, 08:26:57 pmCode: [Select] 
Chart1.SaveToFile(TJPEGImage, 'MyImage.jpg');

See also the demo project in components/tachart/demo/save of your
lazarus installation, or
http://wiki.lazarus.freepascal.org/TAChart_Demos#save
Thanks. I looked in the demo program you said and found the code
similar to above (I didn't see the bit of code in the post before) .
That's what I wanted thanks.

Is there a way of changing the compression ratio / compression
quality/file size of the jpeg of the saved chart (eg. I don't mind if
the file size of the jpeg gets bigger)?
If not it's okay.

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wp · 2014-07-08 18:51

Not quite sure, but could you try this one:
Code: [Select]procedure TForm1.Button1Click(Sender: TObject);
var
  jpg: TRasterImage;
begin
  jpg := Chart1.SaveToImage(TJpegImage);
  try
    TJPegImage(jpg).CompressionQuality:=10;  //10% quality - pretty
low-quality!
    jpg.SaveToFile('d:\temp\test.jpg');
  finally
    jpg.Free;
  end;
end;
The image looks pretty ugly, could be 10% quality - I guess it works.

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Pi · 2014-07-08 19:05

Yes, thanks a lot, that works