Feature Extraction Patents (Class 382/190)
- Slice codes (Class 382/196)
- Directional codes and vectors (e.g., Freeman chains, compasslike codes) (Class 382/197)
- Pattern boundary and edge measurements (Class 382/199)
- Point features (e.g., spatial coordinate descriptors) (Class 382/201)
- Linear stroke analysis (e.g., limited to straight lines) (Class 382/202)
- Shape and form analysis (Class 382/203)
- Local neighborhood operations (e.g., 3x3 kernel, window, or matrix operator) (Class 382/205)