When I first read this, I thought the OP was saying he has a script that displays an image when the mouse is pressed down. However, when he pushes a button to open the menu, the mouse down is also registered and showing the image, and that is not desired.
If that’s the case, you should check like this:
if(Input.GetMouseButtonDown(0) && !EventSystem.current.IsPointerOverGameObject()) image.SetActive(true);
If you meant something else, sorry 
If it’s not what @dgoyette said, perhaps you can try to explain it a little better.
Please take a moment to look at this page for how to post code on the forums, nicely formatted and easy to read: Using code tags properly
Please try to re-read your post after you submit and edit any glaring mistakes. (ie: random ‘/’ or ‘!’ in your message lol)