Scans and OCR
A scan is a picture of a page, so you cannot search it or copy text out of it until optical character recognition reads the letters. These guides cover getting usable text from phone photos and scanned PDFs, what makes recognition fail, and how to tell whether a PDF already has a text layer.
How-to
Scanned Document to Text: How to OCR Phone Scans and PDFs
Scanned document to text: get a clean phone scan, run OCR on an image or PDF, check the per-page confidence, and know when to skip OCR. Printed English only.
Updated