Other PDF Issues

How to Fix Unclear or Merged Text in Scanned PDF Files

Adam Davis Oct 19, 2026 868 views

Question details

The user needs to fix blurry, unclear, or merged text in a PDF created from a photographed or scanned document.

How to Fix Unclear or Merged Text in Scanned PDF Files

Product: PDF
Device & OS: not provided
Scenario: Creating or reading a PDF from a scanned document or photograph where text legibility is critical.
Observed behavior: Text within the scanned PDF appears blurry, pixelated, unclear, or characters are merged, making it difficult to read or process.

Before you start

Check the original source document to ensure it is clean and legible. Blurry source materials or smudged ink will naturally result in poor-quality scans.

Solution 1Recommended

Re-scan the Document with Higher Resolution

Increasing the DPI (dots per inch) and adjusting contrast during the scanning process prevents text from blurring or merging.

Low scanning resolution is the most common cause of merged or unreadable text. Re-scanning with optimized settings ensures the scanning hardware captures enough detail for sharp characters.

Open scanning preferences

Open your scanner software and locate the 'Resolution' or 'DPI' settings before initiating the scan.

Increase DPI

Change the resolution to at least 300 DPI for standard text, or 600 DPI if the original text is exceptionally small.

Adjust contrast

Find the contrast and brightness sliders in the scanner settings and adjust them to ensure the black text stands out clearly against the white background.

Save and convert

Save the new scan as a high-quality image or scan it directly as a PDF document.

Re-scan the Document with Higher Resolution

Optimal Scanning Settings: Scanning at 300 DPI in grayscale or black-and-white mode is the industry standard for maximum clarity and Optical Character Recognition (OCR) accuracy.

Solution 2

Enhance Photographed Documents Before Conversion

If using a smartphone or digital camera, optimize the image lighting and cropping before converting it to a PDF.

Solution 3

Use OCR Tools to Recognize and Clear Text

Running Optical Character Recognition (OCR) can convert blurry scanned images into crisp, editable digital text.

Efficient PDF Scanning and OCR

Use WPS Office to Scan and Extract Clear Text from PDFs

WPS Office provides built-in tools to convert high-quality images to PDFs and a powerful OCR feature to accurately recognize and extract text from scanned documents, ensuring clear readability and easy editing.

1. Open WPS PDF tools: Launch WPS Office and click on 'PDF' on the home screen to access the PDF toolset.
2. Convert images to PDF: Select 'Picture to PDF' to convert your high-quality scans or optimized photos into a clean PDF document.
3. Launch OCR: To clarify or extract text from an existing scanned PDF, open the file and click on the 'OCR' button in the top toolbar.
4. Extract clear text: Select the area of text or the entire page, choose the document language, and click 'Extract Text' to generate crisp, editable content.

Advanced OCR technology to accurately recognize and clear up scanned textFully compatible with all standard Microsoft Office and Adobe PDF formatsBuilt-in image-to-PDF tools for cleaner document conversionsLightweight and user-friendly interface for seamless document management

microsoft office alternative - wps office

Frequently Asked Questions

Why does my scanned PDF text look merged together?

Text often appears merged when the scanning resolution is too low (typically below 300 DPI) or the contrast setting fails to distinguish the thin white spaces between letters. Re-scanning the original document at a higher DPI can immediately resolve this.

Can I fix a blurry PDF without re-scanning the original document?

If you cannot re-scan the document, you can try using PDF software with OCR capabilities. OCR analyzes the document and converts the blurry shapes into clean digital text. Alternatively, you can extract the images from the PDF and use photo editing software to artificially sharpen them, though results will vary based on the original quality.

Does converting images to PDF compress them and cause blurriness?

Yes, many PDF converters apply compression to reduce the final file size, which can degrade image quality and make text appear blurry or pixelated. Check your PDF converter's settings before converting and ensure it is set to 'High Quality' or 'Lossless' compression.

What is the best image format to save a scan before making a PDF?

It is best to save scans in a lossless format like PNG or high-quality TIFF before converting them to PDF. Avoid highly compressed JPEGs, as they introduce visual artifacts around the edges of text, making characters look fuzzy or unclear.

PDF Troubleshooting