# Scan filters & enhancement — clean up a scan, no upload

> Apply flatbed-quality scan filters — grayscale, high-contrast black & white, or color boost — plus brightness and contrast, all in your browser with no upload.

Apply flatbed-quality scan filters — grayscale, high-contrast black & white, or a color boost — and fine-tune brightness and contrast to make a photographed document crisp and legible. All the processing stays in your browser.

Lighting is what betrays a phone scan — shadows, gray backgrounds, uneven exposure. Scan filters counteract that: black & white thresholding turns a dim photo into crisp document-grade text, grayscale preserves subtle marks, and color boost keeps anything that needs to stay colorful readable.

The brightness and contrast controls let you rescue an over- or under-exposed capture rather than re-shooting it, and applying across the session keeps a multi-page document uniform.

Square pages up first with Crop & de-warp and Deskew, then finish with Build PDF, add OCR, or shrink with Compress scan.

## How to

1. **Add a page.** Bring in a scanned or imported page.
2. **Pick a filter.** Choose grayscale, black & white, or color boost.
3. **Adjust.** Tune brightness and contrast for clean, readable output.
4. **Apply.** Enhance all pages, then continue to export.

## FAQ

### Which filter should I use?

Black & white is best for text documents and smallest in file size; grayscale suits pages with pencil or shading; color boost keeps stamps, highlights, and photos vivid.

### Does the black & white filter make text sharper?

Yes. High-contrast thresholding removes the gray haze of uneven lighting, leaving crisp black text on white — the classic clean-scan look.

### Can I apply a filter to every page at once?

Yes — the chosen filter and adjustments apply across the whole scan session for a consistent result.

### Are my pages uploaded to filter them?

No. Filtering is canvas work done in your browser tab, so the pages never leave your device.


## Related tools

- [Crop & de-warp](https://www.safepaper.app/scan/auto-crop)
- [Deskew](https://www.safepaper.app/scan/deskew)
- [Build PDF](https://www.safepaper.app/scan/to-pdf)
- [Compress scan](https://www.safepaper.app/scan/compress)

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