# Document scan cleanup

> Browser-only file conversion. Selected files are processed on this device and are not uploaded to a conversion server.

Source: https://localconverter.tech/scan-cleanup

Improve a photographed document using automatic page perspective correction, small-angle deskew and a choice of black-and-white, grayscale or colour cleanup. The output is a new PNG image suited to reading or a later OCR step. Review page borders and handwriting because automatic cleanup can remove useful faint marks.

## Useful tasks

- Straighten a photographed printed page
- Improve contrast before English OCR
- Create a clearer grayscale receipt scan

## Steps

1. **Choose one page image**: Add a supported still scan of no more than sixteen million pixels. A clearly visible page boundary helps the automatic perspective detector identify the document.
2. **Select geometry correction**: Enable page perspective correction for an angled photograph and deskew for small text-line tilts. Disable a correction when the original framing is already accurate.
3. **Choose cleanup and run**: Select black and white, clean grayscale or contrast-enhanced colour. Run Create output to apply the chosen corrections and save a cleaned PNG image.
4. **Check retained page content**: Download the result and compare its borders, faint writing and small print with the original. Confirm the page detector has not cropped away necessary content.

## Settings

- **Detect document and correct perspective**: Turn “Detect document and correct perspective” on only when it matches your intended result. The initial state is on. Read the workflow and output limitations below when this changes how the original content is processed.
- **Correct small skew**: Turn “Correct small skew” on only when it matches your intended result. The initial state is on. Read the workflow and output limitations below when this changes how the original content is processed.
- **Cleanup**: Choose cleanup according to the result you need. Available choices: Black and white; Clean grayscale; Contrast enhanced colour. The initial selection is Black and white.

## A photographed page before OCR

A printed page is photographed at a slight angle with uneven lighting. Enable perspective and deskew, then try black-and-white cleanup. Inspect the PNG for lost punctuation or handwriting before sending the clearer image to the English OCR tool.

## Check the result

Upload a supported file, adjust the settings and create the output. Automatic page detection works best with clear page borders. Review perspective and handwriting before use. Open the saved output in the app or workflow where you plan to use it. Check one representative result before repeating the same settings with more files. The original files stay unchanged.

## Limits

- Browser cleanup uses page-edge perspective correction, text-line deskew and local thresholding. Review page boundaries and small text after processing.
- Files are processed on this device. Browser memory and engine-specific limits apply. Save results before reloading.
- Automatic page detection works best with clear page borders. Review perspective and handwriting before use.
- Upload one file with a combined size of at most 100 MB. The completed output must fit within 200 MB.
- Files are checked by the local engine; a matching filename alone is not proof of valid contents.
- Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first.

## Questions

### Does cleanup recognize the document text?

No. Cleanup changes the image’s geometry and appearance and exports PNG. To obtain text or a searchable PDF, pass the cleaned image through the separate English OCR tool after checking that the content remains intact.

### Which cleanup mode retains colour?

Contrast-enhanced colour retains a colour image while adjusting local contrast. Grayscale removes colour, and black-and-white thresholding simplifies the page most aggressively. Choose the mode according to whether colour or faint markings carry useful information.

### Why was the page border detected incorrectly?

Automatic perspective detection depends on clear page edges and a plausible document contour. Background objects, shadows or a clipped page can confuse it. Disable perspective correction when the detected geometry removes or distorts required content.

### Can cleanup restore unreadable handwriting?

Cleanup can improve contrast but does not reconstruct missing strokes or guarantee handwriting readability. Aggressive thresholding may remove faint marks, so compare the result with the original and prefer grayscale or colour when subtle tones matter.

### Does Document scan cleanup upload files to another service?

Processing runs in this browser, on your device. Files and pasted input are not uploaded to a conversion server. The website and required engine assets must load first; large operations depend on available device memory.

### Can I continue after changing pages?

Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first.

## Related guides

- [Compress image](https://localconverter.tech/compress-image.md)
- [Resize image](https://localconverter.tech/resize-image.md)
- [Crop & rotate image](https://localconverter.tech/crop-image.md)
- [HEIC / HEIF converter](https://localconverter.tech/heic-converter.md)
- [JPG to JPG](https://localconverter.tech/jpg-to-jpg.md)
- [JPG to PNG](https://localconverter.tech/jpg-to-png.md)