Magento2: Product image is accessible directly without watermark

[websolpro]

Hi,

For example product image is here in cache.

https://domain.com/media/catalog/product/cache/b7106f7fb8dffd4e9354fdeb2f685221/t/a/t_h_watch_1.jpg

Actual image is here without watermark.

https://domain.com/media/catalog/product/t/a/t_h_watch_1.jpg

People can directly access to all images by removing "cache/b7106f7fb8dffd4e9354fdeb2f685221". 

How i can restrict it without affecting SEO?

Thanks.

Regards,

Farrukh

[Sanjay Jethva]

Please upload the actual watermark picture from admin, then if anyone can remove the cache then also they can visit the watermark picture.