multitouchmalli

Multitouchmalli is a framework in human-computer interaction for describing how multitouch input is captured, processed, and interpreted by a digital system. It provides a formal basis for representing multiple simultaneous touch contacts and the gestures they produce, enabling designers and engineers to reason about input semantics independently of hardware specifics.

In the model, each contact point is characterized by an identifier, position coordinates on the sensing surface, a timestamp, and optional attributes such as pressure, size, or orientation. The system maintains a set of active contacts and tracks their motion over time, addressing the contact association problem: keeping consistent identities for finger traces across frames and handling finger merges, splits, and occlusion.

The multitouch processing pipeline typically includes sensing, filtering, contact tracking, and gesture recognition, followed by event dispatch to the user interface. Gestures are defined as temporal-spatial patterns of contact changes, such as taps, pans, pinches, rotations, and multi-finger drags. The model supports customization of gesture vocabularies and thresholds to balance responsiveness and robustness.

Applications span smartphones, tablets, large touch displays, and interactive surfaces. The multitouchmalli informs platform-agnostic design, enabling cross-device compatibility and consistent user experience, while accommodating device-specific capabilities such as maximum simultaneous contacts and pressure sensitivity. Limitations include occlusion, finger identification errors, latency, and power constraints, as well as the challenge of designing intuitive gestures that generalize across contexts.