Attention: This app was created in 2016. I was a beginner to Android development and Computer Vision back then. So don't expect a perfect code please. Over the years I updated the dependencies and converted it to Kotlin, while the business logic remained unchanged.
Note: Originally I targeted min SDK 14 (Android 4), more architectures ("mips", "mips64", "armeabi") and OpenCV 3 with this project. Nowadays the repo uses newer versions. If you need to support older devices, then you can look back in the repo's Git history.
- Uses the camera image to search for a specified template image within it via a feature matching approach using the OpenCV C++ library. The detected object is marked with lines within the scene. This can be used to e.g. find a logo.
- uses an async approach (Coroutines), that means that not every frame will be searched for the object and the GUI stays fluent/responsible
- the OpenCV Java library is used as well for loading the template image. The processing on the other hand is done by the OpenCV C++ library only.
- currently the async calculated image is painted over the live camera preview which can be seen on the edge. This might be changed in the future.
- More computer vision projects at https://michaeltroger.com/computervision/
- IDE: Android Studio (tested with 2023.3.1)
- Android SDK & NDK
- Template image location: res/drawable Changeable in CameraPreviewView
- The passing of the camera frame data from Java to C++ and the async approach is based on Jay Rambhia's AsyncCamera https://github.com/jayrambhia/AsynCamera
- The feature matching is based on this official OpenCV tutorial http://docs.opencv.org/2.4/doc/tutorials/features2d/feature_homography/feature_homography.html Unlike in this application their version is using OpenCV 2 and is for use with static images files
- This C++ library integration builds on code from the Android Open Source Project: https://github.com/googlesamples/android-ndk/tree/master/hello-libs