instance segmentation of defects
**Instance Segmentation of Defects** is the **detection and pixel-level delineation of each individual defect instance** — combining object detection (where is each defect) with semantic segmentation (what shape is it), distinguishing separate defects even when they overlap or touch.
**Key Architectures**
- **Mask R-CNN**: Extends Faster R-CNN with a mask prediction branch for each detected instance.
- **YOLACT**: Real-time instance segmentation combining detection and prototype masks.
- **SOLOv2**: Directly segments instances without explicit detection, using dynamic convolutions.
- **Cascade Mask R-CNN**: Multi-stage refinement for higher-quality masks.
**Why It Matters**
- **Individual Counting**: Counts separate defects even when they touch or are closely spaced.
- **Per-Defect Metrics**: Computes area, shape, orientation for each individual defect independently.
- **Kill Probability**: Per-instance analysis enables individual kill probability estimation for each defect.
**Instance Segmentation** is **giving each defect its own identity** — separately outlining and classifying every individual defect for precise per-defect analysis.