# unpaper/unpaper

A post-processing tool for scanned sheets of paper.

Repository: https://github.com/unpaper/unpaper
Canonical: https://ross.abutalabs.com/products/unpaper
Language: C
License Family: other
Last push: 2024-07-11T20:44:57+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5498, "days_push": 783, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1198, forks 94 (observed 2026-08-28T04:03:57.696340+00:00)

## What it is
unpaper is a command-line post-processing tool for scanned sheets of paper, especially book pages from photocopies. It cleans dark edges, deskews pages, and improves readability before PDF conversion or OCR.

## Use cases
- clean up scanned book pages before converting to pdf
- deskew crooked scanned pages automatically
- remove dark edges from double-sided book page scans
- preprocess scanned images for better ocr results
- batch process scanned sheets of paper

## When to choose
- you scan book pages and want cleaner, straighter output
- you need a lightweight C tool with only ffmpeg as a dependency
- you want automated preprocessing before OCR pipelines

## When to avoid
- you need a GUI for manual image cleanup
- you work with born-digital PDFs rather than scanned images
- you need per-page interactive editing rather than batch processing

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: image-processing, ocr
- domain: image-processing, pdf, developer-tools
- platform: windows, cli, cross-platform
- tags: scanned-documents, deskew, book-scanning, c, linux, macos

## Member repositories
- unpaper/unpaper (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:57.696340+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:21:11.911208+00:00, confidence not recorded.
  - readme: https://github.com/unpaper/unpaper (fetched 2026-08-28T04:03:57.696340+00:00, sha a6364c2620d3)
- Data as of 2026-08-30T08:39:29.467469+00:00.