---
name: Project architecture patterns
description: Key architectural decisions, module locations, and integration patterns discovered during implementation
type: project
---

## First full implementation completed 2026-03-14.

**Why:** Bring the scaffold to a fully compilable, runnable state.
**How to apply:** Future work extends from this baseline.

### Module locations
- `src/config/AppConfig.h/.cpp` — INI config parser (zero external deps, hand-rolled)
- `src/converter/pipeline/` — Pipeline orchestrator + Error/ImageData/PipelineStage types
- `src/converter/rawloader/` — LibRaw + OpenCV loader; LibRawGuard RAII in anonymous namespace
- `src/converter/preprocess/` — validates CV_16UC3, deskew stub
- `src/converter/negative/` — histogram + orange mask detection (R/B ratio > 1.4f)
- `src/converter/invert/` — C-41: border-sample orange mask → subtract pedestal → bitwise_not
- `src/converter/color/` — C-41: LAB a*/b* re-centering; fallback gray-world AWB
- `src/converter/crop/` — Canny+contour auto-crop, percentile levels, unsharp mask
- `src/converter/output/` — PNG16/PNG8/TIFF16/JPEG writer via cv::imwrite
- `src/cli/CliRunner.h/.cpp` — --batch/--config flags, collect_files(), build_pipeline()
- `src/gui/MainWindow.h/.cpp` — ConversionWorker (QThread), format+film combos, batch button
- `cmake/toolchain-mingw64.cmake` — MinGW-w64 cross-compilation
- `scripts/build-windows.sh` — Cross-compile + DLL collection script
- `config.ini` — Example config with all documented keys

### Integration pattern
Pipeline takes ImageData by value (moved). Loader is called outside the Pipeline and feeds it. OutputWriter is added as the last stage.

### CMakeLists quirks
- LibRaw found via pkg-config on Linux/macOS, find_library fallback for MinGW.
- AppConfig.cpp must be in converter_core sources (it uses OutputWriter types).
- OpenCV version guard lowered to 4.6 (CLAUDE.md says 4.10+ for production).