A Partial Hierarchical Model for Online Low-Resolution Wear Particle Images Classification

Table 1

Feature definitions of wear particles.

Feature	Definition
Area: A	The envelope pixels of wear particle image
Aspect ratio: AR	The ratio of length to width
Roundness: α	The similarity between the shape of wear particles and the circle
Radial edge factor: REF	The ratio of characteristic radius of wear particle to the minimum radius of inscribed circle