How to OCR PDF
Optical Character Recognition (OCR) lets you extract editable text from images or scanned PDF documents. With Tenorshare PDNob, you can easily perform OCR to make your PDFs searchable and editable. This guide provides a clear, step-by-step tutorial on installing the OCR feature and using it on your PDF files.
1. What Is OCR
OCR (Optical Character Recognition) is a technology that converts scanned images or image-based PDFs into editable and searchable text. This is particularly useful when handling scanned documents or printed materials that have been digitized.
2. Download and Install OCR
- Launch the Tenorshare PDNob software on your computer.
- On the main interface, click the "OCR PDF" button.
- Select the desired files from your computer, then click "Open" to load them into PDNob.
- Click the "Download" button to install the OCR functionality if prompted.
3. How to OCR PDFs
- Once the OCR feature is installed, click the "OCR" button on the top toolbar to initiate the OCR process.
- A settings window will appear. Choose the OCR mode based on your needs:
-
Scan to Editable Text
Converts scanned text into fully editable content. After OCR, you can edit, move, copy, or delete text in the PDF just like a regular document. -
Scan to Searchable Text in Image
Keeps the original scanned image intact while making text searchable and selectable. Perfect for indexing or looking up text without editing the layout. - After selecting the appropriate option, click "Perform OCR" to start text recognition.
- After OCR is complete, the recognized text becomes searchable and copyable. Selecting "Scan to Editable Text" allows you to edit the text directly in the PDF.
4. OCR Advanced Settings (Supported in PDNob 2.0)
PDNob 2.0, scheduled for release in mid to late March, introduces OCR Advanced Settings, allowing users to optimize recognition results. Enabling these options can improve accuracy, though it may slightly slow OCR processing.
To access these options, open the OCR settings panel and click Advanced Settings. You can enable or disable specific image processing and text detection features. Refer to the screenshot below for the entry location.
Learn more about these settings in this section:
- Auto Crop Page – Automatically detects content areas and trims unnecessary edges, making pages more compact and improving OCR accuracy.
- Auto Deskew Page – Corrects tilted pages to align text horizontally, enhancing recognition precision.
- Enhance Local Contrast – Improves local image contrast to clarify blurry text, slightly altering original colors.
- Remove Dark Spots – Eliminates small dark noise spots, improving page cleanliness and OCR neatness.
- Remove Noise – Filters out white specks and other interference, clarifying text edges for better OCR results.
- Detect Text on Pictures – Recognizes and extracts text embedded within image regions for comprehensive OCR.
