I guess this new topic is related to this topic: Converting file to image - #14 by rdb
What I still don’t understand: Why do you want to convert a PDF to an image to then use it in the Page Design plugin to create another PDF? Why don’t you simply create one PDF using the Page Design plugin and then merge the Page Design PDF with the other PDF? The latter procedure seems more reasonable to me and for this we also have a documentation: 6. Merge PDF - SeaTable Developer Manual
