On Mon, 10 Feb 2020 at 21:26, ToddAndMargo via users <users@lists.fedoraproject.org> wrote:
Hi All,

If I use the gimp erase tool to remove a customers name
from a screen shot, is it really gone or just not showing?
I want to make sure I don't post any private information.

If you use a basic RGB or indexed color image format
such as PNG the actual pixels are changed.   There 
are image formats that support layers (e.g., CMYK 
TIFF's) where redaction could be done by manipulating
a layer.   It is best to convert images with layers to 8-bit
indexed color for transmission -- less chance for 
hidden data and smaller file size.

With a document format like PDF, editing text is much 
more involved than just putting a black box over the text,
so many redaction tools don't touch the text.   Before 
releasing such documents they should be rasterized or
printed.     

It is good practice to check your redactions with a
different image viewer.

--
George N. White III