How to sort images into with and without watermark?

Question

Watermark

Hello!
There are 10 thousand images. Some of them contain various watermarks, and some do not contain watermarks. On those images that do not contain a watermark, you need to apply it. Because images with and without watermark are chaotically mixed, then it is necessary to separate the images that already contain it before applying the watermark, so as not to apply the watermark twice.
How can you separate watermarked images from non-watermarked images? Are there any ready made solutions?

Answer 1

Taking into account the diversity of watermarks - in the general case, there is no way to solve it.
If all variants of watermarks are known, then you can use them as templates for searching images. If the watermark is highly transparent, then it can be quite difficult to detect (the contrast of its contours will be lower than the contrast of the contours of the background image).
In any case, it is necessary to prepare all variants of these various watermarks for use as templates.
I will not suggest a ready solution.

Answer 2

from what comes to mind to try to train a neural network to search for watermarks, theoretically it will be able to guess in the vast majority of images.