Detect watermark text if exists

Hi I would like to remove images that contains watermark text. Is there any simple way to check whether there's a watermark in the center of the image or not?

I don't need to identify any logo, just want to check if there's a high possiblity that watermark exists. If there's a way to make the watermark text clear, I can use OCR to do text detection.

[Hg]

I guess I will just try machine learning.