Scan documents to PDF, Adobe Acrobat

When you run OCR on a scanned output, Acrobat analyzes bitmaps of text and substitutes words and characters for those bitmap areas. If the ideal substitution is uncertain, Acrobat marks the word as suspect . Suspects appear in the PDF as the original bitmap of the word, but the text is included on an invisible layer behind the bitmap of the word. This method makes the word searchable even though it is displayed as a bitmap.

Note: If you try to select text in a scanned PDF that does not have OCR applied, or try to perform a Read Out Loud operation on an image file, Acrobat asks if you want to run OCR. If you click OK, the Text Recognition dialog box opens and you can select options, which are described in detail under the previous topic.