G PHYSICS
G06 COMPUTING OR CALCULATING; COUNTING
G06V IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
30/00 Character recognition; Recognising digital ink; Document-oriented image-based pattern recognition
G06V30/10 Character recognition
G06V30/18 Extraction of features or characteristics of the image
G06V30/18162 related to a structural representation of the pattern
G06V30/18181 Graphical representation, e.g. directed attributed graph