Title: Faster R-CNN: Towards Real-Time Object Detection with Region Proposal Networks
Contribution:
- (motivation: break the bottleneck in 2 stage detection which is the generating procedure of proposals)
- propose Region Prososal Networks (RPN) for generating proposals who shares conv layers with afterward detection networks
- RPN: several conv layers - regress region bounds and objectness scores at each location on a grid
- used nms on proposal regions based on cls scores
- introduce anchor boxes as references at multi-scales/-aspect ratios
- could be thought as pyramid of filters
- key component for effectively sharing features
- propose an alternating training scheme for the 2 stage detection
- evaluated with different param/structure setting comprehensively (PASCAL VOC/ COCO)
Pros: end-to-end, provided code & detailed hyper-parameters for reimplement