3. To install OpenCV’s extra modules, append `--contrib opencv_contrib` to the python command above. **Note:** the extra modules are not included in the iOS Pack download at [OpenCV Releases](https://opencv.org/releases/). If you want to use the extra modules (e.g. aruco), you must build OpenCV yourself and include this option:
5. The build process can take a significant amount of time. Currently (OpenCV 3.4 and 4.1), five separate architectures are built: armv7, armv7s, and arm64 for iOS plus i386 and x86_64 for the iPhone simulator. If you want to specify the architectures to include in the framework, use the `--iphoneos_archs` and/or `--iphonesimulator_archs` options. For example, to only build arm64 for iOS and x86_64 for the simulator: