Ubuntu – How to convert Powerpoint ppsx (presentation) to pdf

One workaround is to split the image generation and the PDF conversion. First convert the images via convert to A4@300dpi (i.e. 3508x2479), then use sam2p to convert them to PDF and then use sam2p_pdf_scale to convert them to A4.

convert -rotate "90>" -scale 3508x2479 -border 64x64 -bordercolor white in.png out.png
sam2p out.png out.pdf
sam2p_pdf_scale 595 842 out.pdf

Edit: A more complete script:

#!/bin/sh

A4_WIDTH=2479
A4_HEIGHT=3508

H_MARGIN=64
V_MARGIN=64
WIDTH=$((${A4_WIDTH} - ${H_MARGIN} * 2))
HEIGHT=$((${A4_HEIGHT} - ${V_MARGIN} * 2))

for i in "$@"; do
    TMP="/tmp/$(uuidgen).png"
    echo "$i"
    convert \
        -rotate "90>" \
        -scale "${WIDTH}x${HEIGHT}" \
        -border "${H_MARGIN}x${V_MARGIN}" -bordercolor white \
        -gravity center \
        -extent "${A4_WIDTH}x${A4_HEIGHT}" \
        -gravity center \
        -font helvetica -pointsize 80 \
        -fill white -draw \
        "push graphic-context
         translate $((${A4_WIDTH}/2 - 160)), 0
         rotate 90
         text -2,-2 '$i'
         text -2,2 '$i'
         text 2,-2 '$i'
         text 2,2 '$i'
         pop graphic-context
    " \
        -fill black -draw \
        "push graphic-context
         translate $((${A4_WIDTH}/2 - 160)), 0
         rotate 90
         text 0,0 '$i'
         pop graphic-context
    " \
        "$i" "$TMP"
    sam2p "$TMP" "${i}.pdf"
    sam2p_pdf_scale 595 842 "${i}.pdf"
done

# EOF #

OK well, I did some more research and although tohuwawohu's method does work, I found it easier to use a program called pdftoppm to achieve what I wanted done. Since I am pretty much a layperson when it comes to using command line apps, I will do my best to explain how I got this to work for me.

1. Navigate to the folder containing the .pdf you wish to edit and open a terminal there. I did this by using the sample command:

   cd ~/Documents/PDF
   

2. Let's say the file I want to edit is called Sample.pdf What I want to do is use pdftoppm to create image files of each page of the .pdf. Several formats can be chosen (see the man pages link above) but I prefer to use .png. The basic command looks like this:

   pdftoppm -FORMAT FILENAME.pdf PREFIX
   

   or in the example above:

   pdftoppm -png Sample.pdf Sample
   

   This command creates an image file of each page in the same folder as the original .pdf file with names like Sample-01.png, Sample-02.png and so on. I have tried it with the .png and .jpeg extensions successfully. .jpg is apparently not supported.

3. Then I just use Archive Manager by selecting all the newly-created image files, right-clicking, and choosing "Compress" from the context menu. I then choose the archive format I prefer (in this case .cbz or Comic Book Zip) and create the new archive.

4. Now I have a shiny new .cbz file called Sample.cbz which I can then view with my Comix reader!

Hopefully what I have posted above makes enough sense that someone else can learn from it. If I need to change it in any way please let me know.