Reproject

Convert coordinates between reference systems — a fast, modern Windows app.

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Reproject transforms geographic and projected coordinates between reference systems (CRS), backed by the full EPSG catalogue. It is a WinUI 3 desktop app built on the CrsKit geodesy library.

Features

• Rich EPSG picker — pick source and target systems by searching on EPSG code or name, browsing by category (geographic 2D/3D, projected, vertical), building a compound system (horizontal + vertical), pasting raw WKT, or reusing favorites. Double-click to select.
• Live transformation — results update line by line as you type or paste.
• Import / export — coordinate lists (CSV/TXT) and CRS definitions (.prj / WKT).
• Remembers your last-used systems between runs.
• Axis orientation control and a details pane (area of use, datum, ellipsoid, units).
• Follows the OS light/dark theme and language.

Languages

Localized into 8 languages, following the OS language (English fallback): English, Spanish, Galician, Basque, Catalan, Italian, French, German.

Built on CrsKit

The coordinate engine is CrsKit, a modern C++ geodesy/CRS library, consumed through its vcpkg package and wrapped for WinUI via a C++/WinRT component.

Reproject                (C# WinUI 3 app)
  → CrsKitInterop.Projection   (C#/WinRT projection)
     → CrsKitInterop           (C++/WinRT component)
        → vcpkg: crskit (+ sqlite3)

Coordinate data (EPSG)

This product includes the EPSG Geodetic Parameter Dataset, owned by IOGP (International Association of Oil & Gas Producers), used under the EPSG Dataset Terms of Use. See the in-app About dialog for the full attribution and disclaimer.

Tech

WinUI 3 · .NET 10 · MVVM (CommunityToolkit.Mvvm) + dependency injection · C++/WinRT interop · vcpkg · SQLite (EPSG).

Build

1. Prerequisites: Visual Studio (WinUI / Windows App SDK workload, toolset v145) and vcpkg with VCPKG_ROOT set. The crskit port is an overlay port of the CrsKit repo; its path is set in CrsKitInterop/vcpkg-configuration.json — adjust it if the library repo lives elsewhere.
2. Provide the EPSG database epsg-fiel.sqlite. The app looks for it in the DIGI21_EPSG_SQLITE environment variable, then at C:\ProgramData\Digi3D.NET\OpenGis\epsg-fiel.sqlite.
3. Open Reproject.sln (x64), restore packages, and build. Building CrsKitInterop makes vcpkg install/compile crskit.
4. Run Reproject (F5).

The native DLLs (CrsKitInterop, CrsKit and sqlite3) are shipped next to the executable and inside the MSIX payload as Content items in the app's .csproj.

License

Reproject is licensed under the Apache License 2.0.

Copyright 2015-2026 Digi21 (José Ángel Martínez Torres).

This product includes the EPSG Geodetic Parameter Dataset, owned by IOGP and used under the EPSG Dataset Terms of Use. The EPSG data is not covered by the Apache license above.