After receiving PDF files containing photos taken with mobile phones, which may include meeting notes, scanned documents, or images of text materials, they often suffer from issues such as blurriness, insufficient lighting, and unclear outlines. This makes it difficult to read key information, significantly affecting the reading experience and the professionalism of the documents. When faced with dozens or even hundreds of pages of such PDF documents, manually enhancing them page by page is time-consuming. However, with the advancement of the times, there are now many tools and methods available to address this issue, enabling a unified improvement in the clarity of images within PDFs and making blurry pictures brighter!
Today I’ll teach you three of the simplest optimization methods, with no complicated content—just a few steps and you’re done! Whether it’s optimizing product photos or making text in PDF images clearer for printing, you’ll be able to do it right after reading. Let’s try it together!
When should you make text images in PDFs clearer so they don’t look blurry?
Scanned files look gray and unclear
Many images in PDFs are produced by scanners or phones. Due to uneven lighting, old paper, and a range of other issues, the images end up with a gray background and blurry text. When previewing, you often find that the more you zoom in on text images, the harder they are to see clearly. Here we can make text images in PDFs clearer and remove the gray background to get clean, clear PDF documents that are easier to read and print.
Enhance professionalism when printing or presenting
If you need to send a PDF to a client, present it, or print it, a grayish background and blurry text edges can make the whole document look unprofessional. By boosting clarity and removing the gray background, you can make the text darker and sharper, the images brighter, and the background cleaner, so it looks like a formal document should.
Restore old PDF archives for easier previewing
Some PDFs come from old archives, photocopies, or on-site documents. These files are often blurry and grayish, making them very tiring to read. By clarifying the text and images and removing the gray background, you can turn hard-to-read old files into easier-to-read versions, and important information won’t be lost behind a heavy background.
Preview of the effect of batch-removing gray backgrounds from PDF text images
Before processing:
After processing:
Method 1: Use HeSoft Doc Batch Tool to make PDF images clear
Recommendation: ★★★★★
Pros:
- Capable of batch-processing hundreds or thousands of PDF files, with a user-friendly interface and simple operations that even novices can quickly handle.
- All files are processed locally, without uploading, protecting user security and privacy.
Cons:
- Only works by installing the software on a computer.
Steps:
1. Open [ HeSoft Doc Batch Tool ], select [PDF Tools] - [Make text in PDF images clear].
2. Use [Add Files] or [Import files from folder] to add the PDF from which you want to remove the gray background. You can also drag files into the area below, then click Next.
3. Enter the settings interface, turn on the [Text Clarity] option, and drag the slider to adjust. If the text in the images still looks pale and blurry, you can turn on the [Sharpness] option and drag its slider to the maximum. Finally, click Next, then Browse, and choose where to save the new files.
4. After processing is complete, click the red path to open the folder, then open the PDF to view the clarified images.
Method 2: Use Adobe Acrobat DC to enhance scanned PDFs
Recommendation: ★★★☆☆
Pros:
- Professional tool with decent results, automatically corrects skew.
- Supports batch processing.
Cons:
- Requires installing Adobe Acrobat DC, suitable for professional users.
- The software is not cost-effective and is very expensive.
Steps:
1. Open the PDF with Adobe Acrobat DC, click Tools - Enhance Scans.
2. Select Enhance Scanned Page.
3. Adjust the Clarity and Contrast sliders, and finally click Enhance.
Method 3: Use online tools to enhance and optimize PDFs
Recommendation: ★★★☆☆
Pros:
- No software installation required.
- Works on mobile devices, and the free version is sufficient.
Cons:
- Requires uploading files to a website server, which may pose privacy risks.
- Usage effects are limited for complex needs.
Steps:
1. Open AVEPDF, select OCR PDF under PDF Optimization.
2. Upload the PDF that has images needing gray-background removal, wait until processing is complete, and then save.
