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Hi,
PDF24 is great, thanks so much for contributing and maintaining it. I'd like to use the watermark feature to protect personal PDF with information picture (such as ID cards) and prevent them from being used for other purposes than the one added on the watermark.
In other words, I need that it is hard to remove the watermark added by PDF 24.
Currently, I'm rather opening the PDF in gimp as an image, add watermark texts to the image (which actually removes the pixels behind, making them hard to guess other than through AI), and then export as PDF using PDF24.
Currently, I understand that PDF24 only add text postscript instruction in the PDF file, but the original images can be retrieved without the watermark (with PDF24 it self using the image extraction feature).
This is great for use cases such as displaying text such as "draft non final version", but not sufficient to make it hard to remove the watermark.
Maybe the current "watermark" feature should inform the user about the recommended use cases for the added watermarks, and remind that they can be easily removed.
It would be great to have PDF24 add a new "image watermark" feature: this would add watermark text rendered directly in the images embedded in the PDF.
Thanks again,
Guillaume.
Hello,
you are right: the watermark is added as a separate layer on top of the page. The images below stay unchanged in the file and can be extracted.
To make the watermark part of the image, you can combine two tools:
- Add the watermark: https://tools.pdf24.org/en/add-watermark
- Rasterize the result: https://tools.pdf24.org/en/rasterize-pdf
Rasterizing turns every page into a single image in a new PDF, so the watermark and the picture below become one image and the original pictures can no longer be extracted separately. In PDF24 Toolbox, the second step is the tool Convert from PDF with the format Secure PDF.
This makes it harder to get the picture without the watermark, but it is no guarantee: the page image itself can still be edited with an image editor.
In addition, Protect PDF lets you set a password and turn off permissions such as copying of contents: https://tools.pdf24.org/en/protect-pdf. Note that such permissions are only respected by programs that observe them.
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