Clean a scanned PDF
Remove blank pages, improve contrast and colors, crop, then compress the document.
What does this template do?
Remove blank pages, improve contrast and colors, crop, then compress the document.
This template improves a scanned document: it removes blank pages, strengthens contrast, crops the dark or grey scanner edges, then compresses the file. The PDF is easier to read and lighter, without OCR.
Pipeline steps
This template automatically chains 6 steps in the Workspace. You can review every setting before running it.
- 1Import a PDF
- 2Remove blank pages
- 3Adjust contrast and colours
- 4Crop a PDF
- 5Compress a PDF
- 6Download the PDF
Why the steps come in this order
Blank pages go first, before the costly processing. Contrast is then strengthened on the remaining pages, cropping removes the edges once the image is corrected, and compression comes last.
When should you use this template?
- Make a slightly grey scanned receipt readable before sending it.
- Remove the dark bands a scanner leaves around pages.
- Lighten a scanned file that is too heavy for an online form.
Local processing in your browser
When the selected modules support local processing, your files stay on your device while the Pipeline runs.
Settings to check
- Contrast: strengthened by a fixed setting (+20); pages are turned into images of about 97 dpi (JPEG quality 82).
- Crop: top, right, bottom and left margins in millimetres, 0 by default; fill them in to remove the edges.
- Compression: “Balanced” by default; “Lossless” avoids a second loss of sharpness.
Example
- Before
- Greyish 20-page scanned file with 2 blank pages and 5 mm dark edges.
- After
- 18 pages with more contrast, cropped by 5 mm and lighter.
Limits to know
- Text is not recognised: use the “Clean and OCR a scanned PDF” template to make it searchable.
- The same margins are removed on every page.
- Each conversion to images reduces sharpness a little: avoid adding strong compression on top.