IDML Pixels Measurements

[ponce52]

If an IDML uses Pixels as the Measurements then when opened by Affinity Publisher the document is 4.166 times too small.

If you switch the Document Units to Points you will see the attached 612 x 792 page and box becomes 146.9 pt x 190.1 pt 

PIXELS.idml

[Pauls]

What's the DPI of the Source document ?

[Joachim_L]

File opens correct for me and px are not pt. Of course the values differ. Example: Document is 1 x 1 inch, translated to cm it would mean 2,54 x 2,54 cm. The dimensions won't change only the values in their different units.

[ponce52]

An InDesign document nor an IDML has a DPI.

There are 2 tests to prove the problem:

1. Open the IDML in Affinity Publisher then change the Document Units to Points and you will see the document is not Letter Size.

2. Open the IDML, colorize the box then Export to PDF, create a new document and place the PDF and you will see the PDF is not Letter Size.

 

Edited September 9, 2021 by ponce52

[ponce52]

Pixels Measurement in InDesign is not based on a DPI (or rather it is 72 which is the same as Points). Therefore, Affinity Publisher's conversion of the IDML is incorrect.

[MikeW]

8 hours ago, Pauls said:

What's the DPI of the Source document ?

20 minutes ago, ponce52 said:

An InDesign document nor an IDML has a DPI. ...

Serif only needs to open your .idml in ID/QXP/Viva Designer, etc., to compare with APub to see the error.

[ponce52]

The specific bug is Affinity Publisher does not set the DPI to 72 when the Measurements defined in the IDML is Pixels.

It coverts the IDML using 612 px to 792 px which is incorrect, but it also means the user has to manually change the DPI to 72, and then switch to Points and then set the DPI to 300 (if desired) and in that order.