Force repaint for clipboard stamp elements

[MaSeife]

I have a question concerning stamp-annotation-elements that were added by copy&paste into a pdf (name contains clipboard). What I found out is that they have an appearance-attribute which has Base64 enconded content. It is some kind of XML-structure (DICT-Element with subelements). I took a look at the content for the same 'image' with different rotations. The 'image'-content remained the same. The only difference I could find was an additional Matrix-Array that was existing, whenever it was not a 'normal' orientation (0 degree). For example for a 90 degree left rotation it was

<ARRAY KEY="Matrix">
<FIXED VAL="0"/>
<FIXED VAL="1"/>
<FIXED VAL="-1"/>
<FIXED VAL="0"/>
<FIXED VAL="55.502362"/>
<FIXED VAL="0"/>
</ARRAY>

So I wanted to be clever and 'simulate' the rotation by decoding the appearance-value, adding a Matrix-Array (in relation to the rotation), encoding it back to Base64 and assigning this new value to the appearance-attribute before the annotations were added back to PDF-XChange. The problem I have: the image/stamp is still shown in 'normal' orientation afterwards - even with the new appearance-value. Is there some kind of trick to force a repaint or something? At first I thought it might be a problem of an old version of PDF-XChange-Editor (we were using some 7.x-version) but it's the same behaviour in a newer version I have tried (10.1.0 - build 380).

In the attached images you can see how the clipboard-Stamp (the about-Dialog was used for it) looks after the insertion into the PDF (as an annotation) and then after the content-processing + rotation. The size and position of the element is as expected, only the orientation and scale of the image is wrong.

Before:

Stamp-Element before.png

Afterwards:

Stamp-Element afterwards.png

For non-clipboard-stamp-elements, where the image content is somewhere in the filesystem, the workaround is to simply clear the content of the stamp-element. Afterwards the stamp is displayed as expected (e.g. rotated the right way). But that doesn't work for clipboard-stamp-elements since the 'image information' is only available within the encoded appearance-Attribute and in that case clearing the content only leads to an empty square.

[Tracker Supp-Stefan]

Hello MaSeife,

I have asked my colleagues from the dev team to take a look at this topic and get back to you as soon as possible!

Kind regards,
Stefan

[MaSeife]

Hi Stefan,

did you get any feedback from the dev team?

Regards,
Markus

[Tracker Supp-Stefan]

Hello Markus,

I can not see a reply - so I've asked once again and will chase this so that I can get you further information as soon as possible!

Kind regards,
Stefan