How to remove repititve pattern from an image

Question

I have to clean images for my OCR. Some of them have text of quite pale gray color above complex background.

After some modifications I've got result like this:

Can I remove this repititve squama-like pattern without bluring and denoising because it prevents the first symbol 'x' and last '6' from recognition?

I'm currently working with cropped fields and don't have big picture with me). Here is link for original images

FFT did some job with that weird mask, but it isn't ok.