Across the last 50 paper filings, show the pattern in OCR failures and where I lose time (bad resolution, skew, handwr…
Open your scanned PDF in Adobe Acrobat.
Go to All tools and select Scan & OCR.
From the left panel, select Enhance Scans.
Adjust the image borders if needed by dragging the blue handles to tightly frame the document content.
Use the available enhancement options to deskew, adjust contrast, and remove background as needed for clarity.
Best practiceImproving contrast and removing background noise before OCR can significantly increase text recognition accuracy, especially for faded or uneven scans.
Click Apply to save the image enhancements.
Return to the Scan & OCR pane and select Recognize Text.
Choose In This File to run OCR on the current document.
Click Recognize Text to start the OCR process.
NoteIf the document was previously OCR'd, Acrobat may prompt to re-recognize text; confirm to proceed if needed.
Save the enhanced, OCR-processed PDF.
Enhancing the image before running OCR helps Acrobat recognize text more accurately in poor-quality scans.
This runs in the Acrobat app - there is no separate API for this task.
Renderable text means the PDF page already contains actual text characters, not just an image. Acrobat's OCR feature is designed to work on image-only pages. If it finds renderable text, it stops because it thinks the text is already there and doesn't need to be recognized. This prevents it from trying to 'read' text that is already machine-readable.
OCR accuracy depends a lot on the quality of your scan. If your document is blurry or has low resolution, the OCR might not recognize the text correctly, or it might make many mistakes. It's best to scan documents at a high resolution, like 300 dpi, to give OCR the clearest image to work with. If the original scan is very poor, OCR may not be able to fix it perfectly.
Selecting the correct language before running OCR is very important because it helps the software recognize characters and words accurately. Different languages have different alphabets, spellings, and grammar rules. If you select the wrong language, the OCR engine might misinterpret letters or fail to form correct words, leading to many errors in the recognized text. This ensures the best possible search results.
| Feature | Regular PDF (image-only scan) | OCR'd PDF (searchable scan) |
|---|---|---|
| Text Selectable | No, text is part of an image | Yes, text can be selected and copied |
| Searchable | No, cannot search for words | Yes, you can search for words and phrases |
| Editing Text | Cannot directly edit text | Can sometimes edit text after recognition |
| File Origin | Often from scanning a paper document | Created from a regular PDF using OCR |