Modifying PDF scans in Photoshop appears as only one layer and not the complete flattened image

Hello All,

I had this problem several times: after scanning a document in PDF, I open it in Acrobat Pro, then I want to add some elements in Photoshop such as stamp or signature.

If I do Tools/Modify, then right-clic "modify into photoshop", I get an image under Photoshop which looks like a layer of a composite document. This might be a problem generated by my scanner, I don't know.

Sometimes I get the automatic OCR which starts, which separates the image blocks. But I know how to disable this.

However it would be good if I could "flatten" the file before sending it to PS.

But what is the appropriate way of doing that?

Do I have to "save" a reduced version of the PDF?

Anyone knows of a quick way of doing that, which could save time?

Thanks for any help.