The -w option gives the output paper width, and the -h option gives the output paper height, normally specified in cm or in to convert PostScript's points (1/72 of an inch) to centimeters or inches. The -p option can be used as an alternative, to set the output paper size to a3, a4, a5, b5, letter, legal, tabloid, statement, executive, folio, quarto or 10x14. The default output paper size is @PAPER@.
The -W option gives the input paper width, and the -H option gives the input paper height. The -P option can be used as an alternative, to set the input paper size. The default input paper size is @PAPER@.
Psresize normally prints the page numbers of the pages output; the -q option suppresses this.
psresize -PA4 -pletter in.ps out.ps