Point Tracker
Description
This app demonstrates the use of a tracker for sparse 2D feature points.
Feature Point Tracking
Feature points are tracked from frame to frame for as long as possible. Additionally, the tracker actively adds new feature points in empty regions, ensuring a steady supply of points to track.
Database and Visualization
The tracker stores a historical record of all feature points in a database, Database, efficiently maintaining image coordinates for each point across multiple previous frames. The application visualizes this database by drawing a path for each feature point, showcasing its image coordinates from previous frames – also known as tracks.
Demo and Implementation
The demo utilizes a platform-independent class called PointTrackerWrapper, which acquires input media and returns an augmented image with point paths (tracks). This class serves as a wrapper around the core tracking logic, implemented in the Tracking::Point::PointTracker class.
Building
- Android
- iOS
- macOS
- Windows
Ensure the third-party libraries have been built for Android for all of the required Android ABIs. Let's assume the base location for third-party libraries is ${HOME}/install_ocean_thirdparty, i.e., the Android versions will be located in ${HOME}/install_ocean_thirdparty/android_${ANDROID_ABI}....
# Define this so that Gradle (and CMake) can find the third-party libraries.
export OCEAN_THIRDPARTY_PATH="${HOME}/install_ocean_thirdparty"
# Change into the directory with the Gradle config of this project
cd ${OCEAN_DEVELOPMENT_PATH}/build/gradle/application/ocean/demo/tracking/pointtracker/android
# In ./app/build.gradle.kts, ensure that only those Android ABIs are enabled for which the corresponding third-party libraries have been built. Otherwise, your build will fail, cf. the [general build instructions](https://github.com/facebookresearch/ocean/blob/v1.0.0/building_for_android.md#4-building-the-ocean-android-demotest-apps).
# Build the debug and release APK of this
./gradlew assemble
# Install the desired APK
adb install app/build/outputs/apk/debug/app-debug.apk
adb install app/build/outputs/apk/release/app-release.apk
By default, the log output will be displayed on the screen of the phone as well as in the Android logs, which can be displayed using:
adb logcat -s Ocean
Ensure the third-party libraries have been built for iOS. Then follow the general setup for building iOS apps using XCode. Once the generation of the XCode project is complete, open it and search for application_ocean_demo_tracking_pointtracker_ios in the scheme at the top. Then hit CMD-R to build, install, and run the app and follow the instructions.
Ensure the third-party libraries have been built for macOS. Then follow the instructions to build the Ocean code base. Let's assume you're building Ocean with the release build config:
cd ${OCEAN_DEVELOPMENT_PATH}
# Build the third-party libraries
./build/cmake/build_thirdparty_linuxunix.sh -c release -l static -b "${HOME}/build_ocean_thirdparty" -i "${HOME}/install_ocean_thirdparty"
# Build and install Ocean
./build/cmake/build_ocean_linuxunix.sh -c release -l static -b "${HOME}/build_ocean" -i "${HOME}/install_ocean" -t "${HOME}/install_ocean_thirdparty"
# Execute the demo app (a bundle)
open ${HOME}/install_ocean/macos_static_Release/bin/application_ocean_tracking_pointtracker_osx.app
Alternatively, generate a XCode project for Ocean and search for application_ocean_tracking_pointtracker_osx in the schemes at the top. Then hit CMD-R to build and run the app.
TODO