An experiment with opencv-rust and basically not much more than the multi-scale face detection demo (using a frontal-face Haar cascade) on the first video capture device that can be found.
To run it, execute
cargo runTo exit, press ESC.
If you get errors such as
[ WARN:0] global ./modules/videoio/src/cap_gstreamer.cpp (1100) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
[ WARN:0] global ./modules/videoio/src/cap_gstreamer.cpp (2075) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module v4l2src0 reported: Internal data stream error.
[ WARN:0] global ./modules/videoio/src/cap_gstreamer.cpp (651) startPipeline OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global ./modules/videoio/src/cap_gstreamer.cpp (1257) setProperty OpenCV | GStreamer warning: no pipeline
thread 'main' panicked at src/main.rs:41:9:
Unable to open default camera!
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[ WARN:0] global ./modules/videoio/src/cap_gstreamer.cpp (616) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created
then the default camera parameters are incorrect for your device.
To select different parameters, use the CAPTURE_WIDTH, CAPTURE_HEIGHT and CAPTURE_DEVICE environment variables:
CAPTURE_WIDTH=848 CAPTURE_HEIGHT=480 CAPTURE_DEVICE=1 cargo run --release