If you have a scanned document, such as a scan from an old text or a journal, you will need to convert your scanned PDF to an OCR format. This is because scanned documents are just images that screen readers can’t actually read. Converting them means you add selectable text from the images on the pages.
To convert scans, in Acrobat, in Tools, click Scan & OCR:
Under Recognize Text, click In This File, then click the Settings gear:
In Output you can select either Searchable Image or Editable Text and Images. If your document’s visual layout is very important, you may want to select Searchable Image. If your document’s visuals aren’t as important, you can select Editable Text and Images. This second option may render a more accessible document than the first.
Once you select your settings, click Ok.
Click In this File again, then Recognize Text.
This will convert the scanned images to readable content.