Sometimes you want to remove confidential parts of a PDF file.
Governments do this all the time.
I wanted to do this too.

It turns out to be hard.  Governments get this wrong too.
It is easy to scribble over something but skilled readers can remove these
scribbles.

What I ended up doing was using GIMP.  The best open source tool.  I sure
didn't want to put my confidential stuff through an internet tool

When loading the document into GIMP, it
naturally
puts each page in a different layer.  That's not a great model but it kind
of works.  If your document is too big, break it up.

With the layers menu, you will see each layer listed.  Back to front.

For each layer:
        look at the layer menu
        make sure that it is the only layer is visible:
                make sure that the only eyeball icon in the first column
                is for the layer of interest.
        click on the layer's image icon

        Move to the image window.
        select the rectangle selection tool: Tools: Selection Tools:
                Rectangle Select (or other suitable tools)
        for each area to censor,
                select the area
                censor it by your choice of Edit: Fill With FG color
                        or Fill With BG color
                        (you will type these a lot so learn the shortcut)

select all the layers (in the Layers menu: all eyeballs on)

File: Export as: select PDF file type/suffix.  Pick a new name to not
overwrite your original.

The result may be a very large file.  I reduced the size (and quality?)
        $ pdf2ps doc.pdf skinny.ps
        $ ps2pdf skinny.ps skinny.pdf
This probably destroys resolution.
You can use GhostScript directly and have more control.
---
Post to this mailing list talk@gtalug.org
Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk