Abstract: Gestural annotation is described, for example where sensors such as touch screens and/or cameras monitor document annotation events made by a user of a document reading and/or writing application. In various examples the document annotation events comprise gestures recognized from the sensor data by a gesture recognition component. For example, the gestures may be in-air gestures or touch screen gestures. In examples, a compressed record of the sensor data is computed using at least the recognized gestures, document state and timestamps. In some examples the compressed record of the sensor data is used to facilitate consumption of the annotation events in relation to the document by a second user. In some examples the sensor data comprises touch sensor data representing electronic ink; and in some examples the sensor data comprises audio data capturing speech of a user.

Abstract: Speckle sensing for motion tracking is described, for example, to track a user's finger or head in an environment to control a graphical user interface, to track a hand-held device, to track digits of a hand for gesture-based control, and to track 3D motion of other objects or parts of objects in a real-world environment. In various examples a stream of images of a speckle pattern from at least one coherent light source illuminating the object, or which is generated by a light source at the object to be tracked, is used to compute an estimate of 3D position of the object. In various examples the estimate is transformed using information about position and/or orientation of the object from another source. In various examples the other source is a time of flight system, a structured light system, a stereo system, a sensor at the object, or other sources.