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Tue, 09 March 2021 13:50

mubeta
Messages: 77
Registered: October 2006

Member

Hi all,
using PdfDraw object for export an multiplepages report in PDf file result in a very big file when there are images. For reduce the size of the resulting PDF file, I modified the method PdfDraw::DrwImageOp(...) in this way:

void PdfDraw::DrawImageOp(int x, int y, int cx, int cy, const Image& _img, const Rect& src, Color c)
{
	Image img = _img;
	if(!IsNull(c))
		img = CachedSetColorKeepAlpha(img, c);
	
	Tuple2<int64, Rect> key = MakeTuple(img.GetSerialId(), src);
	int q = images.Find(key);
	if(q < 0)
	{
		//q = images.GetCount();
		//images.Add(key, img);
		
	  Image h = sJPEGDummy();
		q = images.GetCount();
		images.Add(key, h);
		data = JPGEncoder(40).SaveString(img);
		img = h;
	}
	
	if(img.GetSerialId() == sJPEGDummy().GetSerialId())
		jpeg.Add(data);
	
	page << "q "
	     << Pt(cx) << " 0 0 " << Pt(cy) << ' '
	     << Pt(x) << ' ' << Pt(pgsz.cy - y - cy)
	     << " cm /Image" << q + 1 << " Do Q\n";
	     
}

This will convert every images in compressed JPEG, that in fact result in a smaller PDF file. But, I'm not sure that when the same image is repeated multiple times in the report, the PDF file will contain this image only once or multiple times. It seems to me that the Tuple2 key is intended for this scope, but in fact if I export a test report with only the same image for mulitple pages, without other content, the file size increase proportionally with the page numbers.
What I'm missing?

Many thanks!!

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