Weird watermarks in pictures

[markhichaam]

Hi guys, 

I have a question regarding our product pictures. When we upload pictures in 800px-800px we see strange watermarks in our productphotos. 
Watermarks in the form of strange tables and squares.  Please see attachement: photo**
** when you can't see the watermark, turn your computerdispalay 45 degrees. 

I have found a thread were a guy has the same problem:

But when i try to upload my pictures in 600px- 600px (300dpi) they look really blurry. 
So my question is, is there someone who encoutered the same problem and has a better solution?

I get this strange watermark with al my pictures
Pictures are uploaded in .JPG
Quality: 800px - 800px 
Watermarks are shown in thumbnails and on the productpage
Only visible on: Windows

And these are the image settings of our prestashop:

 

Hope someone can help us! 

 

 

 

 

 

 

 

Edited November 2, 2017 by markhichaam (see edit history)

[selectshop.at]

What you mean by strange watermarks ? If you don't want to have watermarks in your pictures, so disable the watermark module, or change the watermark there you are wanting to have. Search for the module on back-offie tab "Modules". If pictures are blurred, you need to change on preferences -> images ->  the Images generation options -> compression when you upload your pictures.