The AIP alphabet currently consists of the eight hand poses. Each pose has a P-code that is used throughout the AIP to identify it (’P001’, ’P002’, ...). The eight supported hand poses are:
• P001, open hand. An open palm, with fingers stretched and separated. The palm of the hand faces the camera.
• P002, closed hand. Same as P001 but with fingers tightly in contact.
• P008, thumb-up. The hand forms a fist with emphasized knuckles and the thumb points upwards. The inner side of the hand faces the camera.
• P016, thumb-down. The hand forms a fist with emphasized knuckles and the thumb is down. The back of the hand is facing the camera, and the first phalanx of each finger is visible.
• P032, closed fist. All fingers are folded into a fist and the thumb is placed above the other four fingers. The inner side of the hand faces the camera.
• P101, pointing finger. The hand forms a fist with the index finger stretched out horizontally. The thumb is placed over the index finger. The inner side of the hand is facing the camera.
• P102, scissors. The hand forms a fist with the index and major finger stretched out and well separated from each other. The thumb is folded over the ring finger. The inner side of the hand is faces the camera.
• P201, rotated fist. All fingers are folded into a fist, with the thumb over the index and major fingers. The side of the hand showing the thumb and index fingers is facing the camera.
An application should not have lengthy sets of poses for a single task. To enhance usability, the number of needed gestures per application is recommended to be as low as possible.