A modern, local-first Android document scanner. Capture or import images, apply 22 filters, crop and rotate each page, and export as PDF or JPG.
Built with Kotlin + Jetpack Compose (Material 3) + CameraX, modeled after the MakeACopy feature set.
Home · Auto-crop · Editor · Save menu · Settings
- 📷 Camera capture with in-app preview, flash & front/back flip (CameraX)
- 🖼️ Gallery import (system photo picker — no storage permissions needed) with multi-select — pick as many images as the system allows (up to 100 at once) and they all become pages
- 📄 PDF import — open an existing PDF and its pages become editable pages
- 🧭 Manual crop — drag the four corners or the edges (parallel edge translation), with a snap-to-right-angle assist.
- 🔄 Rotate — rotate a page 90° at a time, either in the editor or while cropping; the editor preview updates instantly
- 🧩 Batch editing — with several pages loaded, the editor's "apply to all pages" switch makes changes hit every page at once
- ✨ Auto-enhance — every page is auto-levelled with hardware-accelerated colour-matrix pass
- 🔎 Full-resolution pipeline — imported photos are kept at their original resolution
- ✨ Document cleanup — Natural, Enhanced and Clean Text (background flattening, CLAHE local contrast, clean-up)
- 🎨 22 filters + Text Watermarks & Overlays
- 🔆 Brightness & contrast sliders
- 📚 Multi-page documents
- 📄 Export — PDF with page formats and quality presets; JPG with configurable quality
- 📨 Inbox Mode — pick a folder (SAF) and every export is automatically saved there too
- ♿ Accessibility Mode — spoken + haptic feedback and volume-key shutter in the camera
- ⬆️ In-app updates — check GitHub Releases feed
- 📤 Share with one tap (PDF or JPG)
- 🗂️ Document library — browse, view, re-share or delete past scans
- 📨 Share-to-scan — open an image from any app with "Send to KrizScan"
- 🌙 Modern Material 3 UI
Scanning, filtering and export all happen on-device — no accounts and no uploads.
Source code and releases available on GitHub: altkriz/KrizScan.
# JDK 17 required
./gradlew :app:assembleDebug # debug build
./gradlew :app:assembleRelease # release build- minSdk: 26 (Android 8.0)
- targetSdk: 36
app/src/main/java/com/kriztech/scan/
├── MainActivity.kt # Compose entry point + volume-key shutter (A11y)
├── App.kt # Navigation + bottom bar
├── A11y.kt # Accessibility Mode: TTS + haptics
├── DocViewModel.kt # Shared state (pages, settings, history)
├── scan/ # The engine
│ ├── Cleanup.kt # OpenCV document cleanup (Natural/Enhanced/Clean Text) + corner detector
│ ├── WarpTarget.kt # Warp target size: Zhang & He projective estimate + fixed ratios
│ ├── ImageFilters.kt # 22 filters (incl. MakeACopy cleanup presets) + Otsu B&W + sharpen
│ ├── CropGeometry.kt # Edge dragging + snap-to-right-angle geometry (MakeACopy port)
│ ├── CropAspectRatio.kt # Crop aspect-ratio presets enforced at warp time
│ ├── PdfImport.kt # PdfRenderer -> page bitmaps
│ ├── BitmapUtil.kt # Rotate/crop/perspective-warp/EXIF/grayscale
│ ├── PdfExporter.kt # android.graphics.pdf PDF writer (page format + DPI presets)
│ ├── MediaSaver.kt # MediaStore saves + inbox folder writes
│ └── Exporter.kt # Export pipeline (PDF/JPG + inbox mirror)
├── data/ # History + settings persistence + PDF page-format/quality options
├── update/Updater.kt # GitHub Releases update check + APK download/install
├── ui/ # Screens (Home, Camera, Editor, Crop, Documents, Settings) + UpdateDialog
└── util/ShareUtil.kt # Sharing via FileProvider
- OpenCV 4.13.0 (Apache 2.0) — corner detection and document cleanup presets, like MakeACopy.
MIT — see LICENSE.