Find duplicated pictures in a pdf file

Acrobat allows you to export all the images in a document (vs. exporting pages as images), they are named according to their original page and position.
Then you can use an image comparison software.

I think the best method would be to export the images as stand-alone files and then use a dedicated tool for looking for duplicates within that set. Doing it in Acrobat is going to be extremely difficult, if at all possible.

There is to my knowledge no integrated tool to do that, and IMHO, it will be difficult to do that, as images may look the same, but may have slight differences which makes comparing them impossible.

In addition, if the technical drawings are vector graphics, they may even not appear as graphics, but a different bunch of vectors.