Question

I’m using GhostScript to convert PDFs to PNGs, the problem is that for each page I’m calling:

gs -sDEVICE=pnggray -dBATCH -dNOPAUSE -dFirstPage=10 -dLastPage=10 -r600 -sOutputFile=image_10.png pdf_file.pdf

Which is not good, I want to pass dFirstPage=10 dLastPage=30 for example and make GhostScript automatically extract each page in a SEPARATE png file WITH the PAGE-NUMBER in the filename, without starting it again with different sOutputFile…

I know it’s probably something simple but I’m missing it…

Also, it would be great if someone can tell me what parameter I need to pass to make ghostscript run in total silence, without any output to the console.

EDIT: Adding %d to the output parameter adds the number of the run, instead of the number of the page. For example:

-dFirstPage=10 -dLastPage=15 -sOutputFile=image_%d.png

results in:

image_1.png, image_2.png, image_3.png etc… instead of:
image_10.png, image_11.png, image_12.png …

Answer 1

Save this as a file

 #!/bin/bash
 case $# in [!3] ) printf "usage : ${0##*/} stPage endPage File\n" >&2 ;; esac
 stPage=$1
 endPage=$2
 (( endPage ++ ))
 file=$3
 i=$stPage
 while (( i < endPage  )) ; do
    gs  -sstdout=/dev/null -sDEVICE=pnggray -dBATCH -dNOPAUSE -dPage=$i -r600 -sOutputFile=image_$i.png ${file}

   (( i ++ ))
 done

Check in the ghost script manual to see if there is a -dPage=${num} option, else use
-dFirstPage=${i} -dLastPage=${i} .

Then make it executeable chmod 755 batch_gs.sh

Finally run it with arguments

  batch_gs.sh 3 5 fileName

(Lightly tested).

I hope this helps.