Project structure

June 12, 2026 · View on GitHub

OpenCV 5.0/
├── source/           Delphi units (OpenCV5.*.pas)
├── wrapper/          C++ DLL opencv_delphi_wrapper.dll
│   └── yolo_postprocess.cpp   custom YOLO X/v5/v8 postprocess
├── package/          OpenCV5.dpk, OpenCV5Vcl, OpenCV5Fmx, OpenCV5Design
├── dcu/              intermediate .dcu (Win64/Release, from IDE)
├── docs/             documentation (English; Russian in docs/ru/)
├── samples/          tests and demos; common/DemoUtils.pas
├── Test/             component projects (Utit2, …)
├── build_all.ps1     build DLL + all executables
├── build_package.ps1 build .bpl / .dcp
├── download_models.ps1
├── ci.ps1
├── bin/
│   ├── bpl/          runtime/design .bpl (build_package.ps1)
│   ├── dcp/          .dcp for package linking
│   └── …             exe, DLL, models/, test.png
└── README.md         short overview + link here

The generator/ folder (binding autogeneration script) is not in git — see Generator.

Two layers

Layer	Directory	Role
Pascal	`source/`	types, CMR, flat API, components
C++	`wrapper/`	`opencv_delphi_wrapper.dll`, SEH, custom postprocess

The application loads opencv_delphi_wrapper.dll, which links against OpenCV. Pascal units are thin wrappers over DLL exports.

Custom Managed Records (CMR)

Types such as TCVMat, TCVFaceDetectorYN, TCVVideoCapture, TCVMOG2, etc. are CMR: memory is released automatically; calling .Free is not required.

API details: Delphi units.

SEH and limitations

The DLL is built with /EHa. On load, Core_installSehTranslator is called (also from OpenCV5.Core initialization). Critical C++ calls are wrapped in try/catch + Core_setLastError.

API	Note
`splitMat`	for `CV_8U` — pure-Pascal `splitMat8u`; create plane Mats upfront (`Create_2`, not `Create_0`)
`imencode`	works in tests and demos
`fastNlMeansDenoisingColored`, `seamlessClone`	not called in `TestOpenCV5.exe`; `DemoSeamlessClone5` — preview, `--try-clone` optional

Webcam: TCVVideoCapture.read(var image: TCVMat) creates an empty CV_8UC3 Mat when Handle = nil.