Across my last [N=12] projects, transcription errors in names and dates have been the main source of mis‑citations tha…
Open the scanned PDF in Adobe Acrobat.
Check if the document is an image-only PDF by attempting to select or search for text.
NoteOCR cannot recognize text if the PDF does not contain images or if the text is already selectable.
Go to Tools and select Recognize Text.
Click Recognize Text and choose In This File.
Review the OCR output for errors or missed text by scrolling through the document.
If OCR accuracy is poor, check the scan quality: ensure the document is at least 300 dpi, not skewed, and has high contrast.
Best practiceLow-resolution, blurry, or skewed scans are the most common causes of OCR failure.
Rescan the original document at 300 dpi or higher, using RGB mode for discolored or older pages.
Best practiceFor best results, avoid scanning with excessive brightness and ensure pages are flat and unmarked.
Repeat the OCR process on the improved scan.
Manually correct any remaining OCR errors by clicking on suspect words to edit and accept corrections directly.
NoteYou can click on suspect words to edit and accept corrections directly.
Save the corrected PDF.
If OCR still fails, try rescanning your document at a higher resolution and check for skewed or blurry pages before running OCR again.
This runs in the Acrobat app - there is no separate API for this task.
This error means the page you are trying to OCR already has real, selectable text, not just an image. Acrobat's OCR feature is designed only for image-based pages. If you see this error, it means the text is already recognized, and you do not need to run OCR again. You can try to select text on the page to confirm it is already 'renderable'.
If your scanned document is blurry, the OCR accuracy will likely be lower. Acrobat needs clear images to correctly identify characters. For the best results, always scan documents at a high resolution, like 300 dpi. If the original scan is poor, try to rescan it at a better quality before running OCR to improve text recognition.
Selecting the correct language helps Acrobat's OCR engine recognize text more accurately. Different languages have different character sets, spellings, and grammar rules. If you choose the wrong language, Acrobat might misinterpret words, leading to more errors in the recognized text. Always match the OCR language to the document's language for the best outcome.
| Feature | Scanned PDF (Image-only) | PDF with Recognized Text (OCR) |
|---|---|---|
| Text Selection | Cannot select text | Can select and copy text |
| Searchability | Cannot search for words | Can search for words |
| File Content | An image of the document | An image with a hidden, searchable text layer |
| Editing | Cannot edit text directly | Can edit text (after fixing errors) |