Computer Vision & Hand Landmark Topology

21-Landmark Skeletal Map

MediaPipe extracts 21 points:

• Point 0: Wrist anchor
• Points 1-4: Thumb ray
• Points 5-8: Index finger ray
• Points 9-12: Middle finger ray
• Points 13-16: Ring finger ray
• Points 17-20: Pinky finger ray

Gesture Classification Logic

• Pointing Gesture: Distance between Index Tip (8) and Wrist (0) is $> 2.5 \times$ Middle Tip (12) to Wrist (0).
• Pinch Gesture: Euclidean distance between Thumb Tip (4) and Index Tip (8) is $< 0.05$ normalized units.