From a6c71bc82545959ead35190fce268710acf07f46 Mon Sep 17 00:00:00 2001 From: Jonas Smedegaard Date: Wed, 7 Jul 2021 16:24:07 +0200 Subject: explain the magic width and height values in resize command --- USE.md | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/USE.md b/USE.md index f4facae..bdd3993 100644 --- a/USE.md +++ b/USE.md @@ -16,5 +16,17 @@ Alternative: ## Resize PDF with crop marks -A3 oversize to A4 oversize: +Ghostscript resizing is done by first defining target size +and then tell to resize content to fit that target with `FitPage`. + +For a PDF document containing bleed and/or crop marks, +setting a simple target `PAPERSIZE` would either scale too much +or (e.g. with `-dUseArtBox`) would loose bleed and crop marks. +Instead we look up original width and height with the command `pdfinfo` +and explicitly set those values scaled down by 21/29.7 +(the ratio between A3 and A4 page formats). + +Example command, +for a PDF document with width 910.24 and height 1258.9: + gs -o output.pdf -sDEVICE=pdfwrite -dDEVICEWIDTHPOINTS=643.60333 -dDEVICEHEIGHTPOINTS=890.131 -dFIXEDMEDIA -dFitPage -dCompatibilityLevel=1.4 input.pdf -- cgit v1.2.3