% SL Script to control PDF generation, center a small input into a larger page

define pdf_page_setup(pagenum) {
  variable delta_x;
  variable delta_y;
  variable targetpagex = 1500;  % Change here your desired output size
  variable targetpagey = 1800;  % should be larger than the input size
  
  delta_x = targetpagex - pageWidth();
  delta_y = targetpagey - pageHeight(); 
  
  % place only if the output size is larger than the input, otherwise do nothing
  
  if (delta_x > 0 and delta_y > 0) {
      	setupPage(delta_x/2.0,delta_y/2.0,0,1,1,0);	
	      setMediaBox(int(targetpagex),int(targetpagey));
  }

}