Method and apparatus continuing action of user gestures performed upon a touch sensitive interactive display in simulation of inertia
A method and apparatus for identifying user gestures to control an interactive display identifies gestures based on a bounding box enclosing points at which a user contacts a touch sensor corresponding with the display surface and permits use of inexpensive and highly reliable grid-based touch sensors that provide a bounding box to describe contact information. In identifying gestures, position, motion, shape, and deformation of the bounding box may be considered. Center, width, height, aspect ratio, length and orientation of the bounding box diagonal may be determined. A stretch factor, defined as the maximum of the ratio of the height of the bounding box to the width of the bounding box and the ratio of the width of the bounding box to the height of the bounding box, may also be computed. Gestures may be identified based on the changes in time of these characteristics and quantities.
1. A computer implemented method performed in a system including a processor coupled to digital data storage and a display having a touch-sensitive display surface, wherein the method comprises the steps of:
in the digital data storage, storing a record defining a collection of multiple user gestures executable by touching the display and for each user gesture storing an assignment of at least one of multiple prescribed operations of modifying subject matter presented by the display;
for each of at least one touch experienced by the display surface, the processor observing one or more characteristics of the touch;
based on data including the one or more characteristics of one or more of the touches experienced by the display surface, the processor identifying from the collection of user gestures at least one user gesture executed by the one or more touches;
the processor identifying the at least one prescribed operation assigned to the executed user gesture, and causing the display to begin modifying the subject matter presented by the display according to the identified operation;
the processor using the one or more characteristics of one or more touches to compute a final velocity for the executed gesture; and
responsive to the executed user gesture ending with a final velocity exceeding a prescribed minimum velocity across the display surface, the processor causing the display to continue the identified operation to visually simulate inertia of the executed user gesture.
2. The method of claim 1 , wherein the one or more characteristics comprise any of:
a current position,
a current velocity,
a current shape,
a current magnitude,
a current intensity,
a current force,
a position history,
a velocity history,
a shape history,
a magnitude history,
an intensity history, and
a force history.
3. A computer implemented method performed in a system including a processor coupled to digital data storage and a display having a touch-sensitive display surface, wherein the method comprises the steps of:
in the digital data storage, storing a record defining a collection of multiple user gestures executable by touching the display and for each user gesture storing an assignment of at least one of multiple prescribed operations of modifying subject matter presented by the display;
for each touch experienced by the display surface, the processor tracking a position history and sensing the magnitude of the touch;
based on data including any of the position history and magnitude of one or more of the touches experienced by the display surface, the processor identifying from the collection of user gestures at least one user gesture executed by the one or more touches;
the processor identifying the at least one prescribed operation assigned to the executed user gesture, and causing the display to begin modifying the subject matter presented by the display according to the identified operation;
the processor using the position history to compute a final velocity for the executed gesture; and
responsive to the executed user gesture ending with a final velocity exceeding a prescribed minimum velocity across the display surface, the processor causing the display to continue the identified operation to visually simulate inertia of the executed user gesture.
4. The method of claim 3 , further comprising the step of:
the processor conducting the identified operation at speeds proportional to the sensed magnitude.
5. The method of claim 3 , further comprising the step of:
responsive to the display surface experiencing a new touch while a previously identified operation is being continued to visually simulate inertia, slowing the modification of subject matter presented by the display according to the previously identified operation, wherein the slowing occurs at a rate proportional to a magnitude of the new touch.
6. An interactive display system, comprising:
a display having a touch-sensitive display surface;
digital data storage containing a record defining a collection of multiple user gestures executable by touching the display and for each user gesture an assignment of at least one of multiple prescribed operations of modifying subject matter presented by the display; and
a processor coupled to the display and the digital data storage, the processor programmed to perform tasks comprising:
for each touch experienced by the display surface, the processor tracking one or more characteristics of the touch;
based on data including the one or more characteristics of one or more of the touches experienced by the display surface, the processor identifying from the collection of user gestures at least one user gesture executed by the one or more touches;
the processor identifying the at least one prescribed operation assigned to the executed user gesture, and causing the display to begin modifying the subject matter presented by the display according to the identified operation;
the processor using the one or more characteristics to compute a final velocity for the executed gesture; and
responsive to the executed user gesture ending with a final velocity exceeding a prescribed minimum velocity across the display surface, the processor causing the display to continue the identified operation to visually simulate inertia of the executed user gesture.
7. The invention of any of claims 1 , 3 , and 6 , further comprising any of:
responsive to the executed user gesture ending with a final velocity not exceeding the prescribed minimum velocity across the display surface, the processor causing the display to cease the identified operation;
responsive to a user gesture ending with a final velocity exceeding the prescribed minimum velocity, causing the display to slow the modification of subject matter presented by the display according to the identified operation, wherein the slowing occurs at a predetermined rate so as to simulate friction;
responsive to the display surface experiencing a new touch while a previously identified operation is being continued to visually simulate inertia, slowing the modification of subject matter presented by the display according to the previously identified operation, wherein the slowing occurs at a predetermined rate so as to simulate friction;
responsive to the display surface experiencing a new touch while a previously identified operation is being continued to visually simulate inertia, slowing the modification of subject matter presented by the display according to the previously identified operation, wherein the slowing occurs at a rate proportional to force exerted by the new touch;
responsive to the display surface experiencing a new touch while a previously identified operation is being continued to visually simulate inertia, slowing the modification of subject matter presented by the display according to the previously identified operation, wherein the slowing occurs at a rate proportional to surface area of the new touch;
responsive to the display surface experiencing a new touch while a previously identified operation is being continued to visually simulate inertia, the processor causing the display to cease the previously identified operation.
8. The invention of any of claims 1 , 3 , and 6 , further comprising any of:
the prescribed user gestures include a LAZY SUSAN user gesture comprising at least one point of user contact with the display surface traversing one of the following patterns: an arc, a substantially straight line;
the prescribed operation associated with the LAZY SUSAN user gesture comprises rotating, as a whole, subject matter presented by the display about a predetermined point;
the prescribed user gestures include a PAN gesture comprising movement of at least one point of user contact with the display surface across at least a portion of the display surface, the prescribed operation associated with the PAN gesture comprises translating, as a whole, subject matter presented by the display in a direction of the movement;
the prescribed user gestures include a ZOOM gesture comprising initiation of two points of user contact with the display surface and then an increase in distance between the points of user contact, the prescribed operation associated with the ZOOM gesture comprises enlarging, as a whole, subject matter presented by the display; and
the prescribed user gestures include a ROTATE gesture comprising an occurrence of two points of user contact with the display surface and then rotation of the points of user contact about a center of rotation, the prescribed operation associated with the ROTATE gesture comprises rotating, as a whole, contents of the display about the center of rotation.