Modify saved pdf to get back to original pictures

Hello! I have some PDFs saved in Adobe Scan, but I didn't realized that some pictures came out automatically cropped. I see that there's an option to modify the PDF, and I could successfully do it with some more recent files, but I found that with some elder ones  I cannot bring the single pictures in their original version anymore. Is there a way I could retrieve the original pictures from those PDFs?

thanks!