Printing QTextDocument with pictures via QPrinter as PDF will result in very big files.

Hello,
when I creating and print an QTextDocument with pictures, witch are stored in the resource system to PDF. the resulting PDF file are very lage. 2 JPEG files with 220kb together will result in an PDF file with 600KB.
Sample:
QPrinter *printer=new QPrinter();
printer->setOutputFormat(QPrinter::PdfFormat);
printer->setPaperSize(QPrinter::A4);
printer->setOutputFileName(/tmp/foo.pdf");
printer->setColorMode(QPrinter::Color);
QTextDocument *doc=new QTextDocument();
doc->setPageSize(printer->paperSize(QPrinter::Millimeter));
QTextCursor cursor(doc);
QTextImageFormat picture1;
picture1.setName(":/picture/top.jpg");
picture1.setWidth(150);
cursor.insertImage(picture1,QTextFrameFormat::FloatLeft);
QTextImageFormat picture2;
picture2.setName(":/picture/right.jpg");
picture2.setWidth(45);
cursor.insertImage(picture2,QTextFrameFormat::FloatRight);
doc->print(printer);