[poppler] Poppler – Assumptions?

[Leonard Rosenthol]

Text positioning in PDF – any compliant PDF viewer – is 100% deterministic.   All of the algorithms for text (or any graphics for that matter) placement are described by the standard – ISO 32000.

That said, a big part of the algorithms for text placement is based on font metrics.  If the fonts are embedded in the PDF – then there is no question about what the metrics are and they will be consistant between implementations and platforms.  However, should the font not be embedded in the PDF, then a viewer is free to substitute any font that it wishes – in which case, the metrics (and glyph shapes, etc.) will vary.

Why, John, what are you concerns?   And have you reviewed ISO 32000 for the information about the PDF standard itself?

Leonard

From: poppler <poppler-bounces at lists.freedesktop.org> on behalf of John Curci <theprefixcyber at gmail.com>
Date: Monday, September 23, 2019 at 12:23 PM
To: "poppler at lists.freedesktop.org" <poppler at lists.freedesktop.org>
Subject: [poppler] Poppler – Assumptions?

Is text positioning from Poppler "perfect"? Is the positioning of text a deterministic
result of the PDF format, or does Poppler make certain assumptions and guesses? What are some assumptions made?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/poppler/attachments/20190924/2dcf870e/attachment.html>