Hello!
I've got a question about the adjustment of the user space units because I think I haven't understood this correctly, yet. I have already searched the PDF specification, the internet and this forum but there were no visible hints who gave me an answer.
PDF assumes a default user space unit of 1/72. I am mapping document elements from another coordinates system into a PDF page, but they use different DPI configurations. The other coordinates system is using 96 DPIs.
I thought that I can adjust the user space units via the special page object entry, "UserUnit". I set this value to:
72 / ownDpis = 72 / 96 = 0.75 // where ownDpis equals 96 in my case
The page dimension in PDF becomes set to:
/MediaBox [0 0 793.70081 1122.51965]
I expected that this page dimension height (1122.51965) represents:
1122.51965 * 1 / 96 = 11.692913020833333333333333333333 inches = 296 millimeters
But later, Adobe Reader displays a page height of 396 millimeters (= 15,59 inches).
What's wrong with my assumptions? Is it possible to adjust the UserUnit so that I can take my 96 DPI coordinates without scaling them to 72 DPI in PDF? How do I use UserUnit? If it's not possible, what's the intention of the UserUnit entry?
Best regards
PAX