ncnn-yolov8 detection and segmentation demo

The yolov8 object detection and segmentation

1.Android yolov8 detection demo
2.yolov8s-seg.cpp
3.yolov8s-obb.cpp

Note: obb & seg have not been completed yet

Export ncnn model

1.export detect model

2.export seg model

3.export detect-obb model

screenshot

Reference：

https://github.com/nihui/ncnn-android-nanodet
https://github.com/Tencent/ncnn
https://github.com/ultralytics/assets/releases/tag/v0.0.0
https://github.com/facebookresearch/detectron2