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Reversing watermark

Posted: 2018-09-28T09:03:47-07:00
by sebmarion
Hi,

Some of my clients apply watermarks to their photos, but our service requires the supply of photos *without* watermarks, and sometimes they have literally lost it.
We can always ask the client for the original watermark file that was used and the applied shading.

My question is, is it possible to reverse the process given the output picture and the original watermark?

I attach a typical watermarked example.Image

Many thanks,

Seb

Re: Reversing watermark

Posted: 2018-09-28T09:14:51-07:00
by fmw42
If you have the exact watermark image that was applied to the background image, then it can be used to remove the watermark. If you do not, then you can try inpainting solutions or some Imagemagick approximations. All 3 approaches are described at https://stackoverflow.com/questions/524 ... -from-jpeg


______________________


Please, always provide your IM version and platform when asking questions, since syntax may differ. Also provide your exact command line and if possible your images.

See the top-most post in this forum "IMPORTANT: Please Read This FIRST Before Posting" at http://www.imagemagick.org/discourse-se ... f=1&t=9620

If using Imagemagick 7, then see http://imagemagick.org/script/porting.php#cli


For novices, see

http://www.imagemagick.org/discourse-se ... f=1&t=9620
http://www.imagemagick.org/script/comma ... essing.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/
https://github.com/ImageMagick/usage-markdown

Re: Reversing watermark

Posted: 2018-09-28T09:52:11-07:00
by snibgo
If the watermark is known, and the process by which it is applied is known, and this is lossless (ie hasn't removed data), and isn't cryptographically secure (it usually isn't), then it can be reversed.

I show some examples at Watermarks.

As Fred says at his link, the watermark can always be painted out and the missing pixels "invented".

Re: Reversing watermark

Posted: 2018-09-30T23:15:52-07:00
by sebmarion
Thanks guys!
My clients have the original so we'll give it a go!