(png1 (format #f "~a.~a" base extension))
(pngn (format #f "~a-page%d.~a" base extension))
(page-count (ps-page-count ps-name))
(png1 (format #f "~a.~a" base extension))
(pngn (format #f "~a-page%d.~a" base extension))
(page-count (ps-page-count ps-name))