Is it possible to make a pdf with different page size in Qt?

If the size of the page is same, then no problem, but I need the page size should be the size of Image(which is variable),

void DgJpgToPdf::convertToPdf( const QStringList& theImagePathList, const QString& theOutputFileName )
{
    QPrinter printer;
    printer.setOrientation(QPrinter::Portrait);
    printer.setOutputFormat( QPrinter::PdfFormat );
    printer.setOutputFileName( theOutputFileName );
    QPainter painter;    
    painter.begin( &printer );
    //printer.newPage();
    foreach( QString  fileName, theImagePathList ){
        QImage imgObj( fileName );    
        printer.setPaperSize( QSizeF(imgObj.width(), imgObj.height()), QPrinter::DevicePixel );        
        painter.drawImage( 0, 0, imgObj );
        printer.newPage();
    }
    painter.end();
}