You are welcome, Daniel!

This can happen when you have to process a bunch of files, combining both PDF, images, and scanned PDFs.

Instead of trying to write a specific code to process each type of file, you can simply standardise all your files to be in the same format, image in this case, since you can not convert images, nor scanned PDFs into native PDFs, or at least it will be more complex thing to do.

I hope this explanation helps. Otherwise, please let me know if there anything else I can help answer.