I also needed to enable C++ exceptions and Run-Time Type Information (flags -fexceptions and -frtti). OpenCV provides compiled versions for Android here: Īlso, what kind of linker flags did you use when compiling your own wrapper C++ code? Specifically, are you using the c++ stl library statically or as a shared dll?įor STL, I used LLVM libc++ shared library (c++_shared). User136939 was wondering how did you get hold of the opencv native c++ (shared/shared) library for the arm achitecture? Did you compile it yourself from the OpenCV source?

Would you be interested in putting up your Android project / wrapper in a github repo we could sample? Seems like we have our work cut out for us. For functions such as thresholding, masking, circleFit, etc. I hope this helps, and I'd be happy to help if you get stuck.Īwesome! Wanting something that will work for both Android and iOS. In my case, I decided to work with SkiaSharp, so that my images are converted to SKBitmap. In this class, I also handle working with IntPtr (which is what I get back instead of uchar*) and converting it to an image I can use in Xamarin. In my Xamarin.Forms project, I created an IVisionService that is implemented in the Xamarin.Android project a by VisionService class that makes calls to the C# wrapper. This project contains a class with a bunch of DllImport statements that bind to the C++ API. I then created a 'Shared Project' (C#) to wrap the C++ API so that it may be called from C#. I then wrapped those classes by functions that don't depend on OpenCV (for example, they return uchar* instead of cv::Mat). In this project, I wrote my own API that does the processing using C++ and OpenCV. Using Visual Studio 2019, I added a 'Dynamic Shared Library (Android)' C++ project to my Xamarin.Forms solution. I developed my solution based on these resources: I have it working for Android, but I think the steps will be similar for iOS. Hi Carlos could you share your implementation? We’re curious about using image processing tools from OpenCV in XF. I haven't found a way to make this smaller, although I haven't tried activating the 'link all' option as suggested above. User136939 Yes, I found a way to make it work, but the problem is that the final binaries are very large (~ 200 MB).

Xamarin forms visual studio 2019