I'm working on writing a technical ebook on Adobe Indesign. There are many engineering drawings and smart-arts (in .png format) which I want to include in it. When I export the book as pdf, the images that are included in it show selection around them when clicked. I want to make the image indiscoverable by the user i.e. the selection should not appear as if the image is part of the text and not like a layer stacked upon it.
I know there is a restrict editing option in pdf settings but it makes the text non-copyable, too. I just don't want the image to be selected but the text (including text inside image). How can I do that?