Very large text extraction

So does the file already contain "real" text which you just want to extract, or do you mean you want to convert the scanned pages into "real" text (via OCR)? The former is easily done in Acrobat. The latter would probably be too much more it to handle, at least in a single go.

@R623 honestly you can't with the free Acrobat Reader Mobile app. Reader is primarily a viewer and a basic annotator; it doesn't have the advanced Optical Character Recognition (OCR) capabilities needed for this task. Instead, you need to upgrade to the paid subscription to Adobe Acrobat Pro, either on a desktop computer or via the mobile app. By upgrading, you would be able to convert a high-resolution image file (like your 4K snapshot) into a text-searchable and editable document.