Watermark for big image

Dear team,
is possible add watermark to big image (picture is shown after click on medium image)?

I think it is very important, because when watermark is not used on big image is unnecessary on medium image.

Hi Igor,
Unfortunately, OS Property doesn't add the watermark into original picture. Because the size of original pictures are difference so OS Property can't find correct place to put watermark. Moreover, their sizes are also big too, and it will need a lot time to process watermark adding.
Thanks
Dam