GRAPHICAL OBJECT MANIPULATION WITH A TOUCH SENSITIVE SCREEN

1 . A method for graphical object manipulation using a touch sensitive screen, the method comprising:

detecting a presence of two user interactions within a defined boundary of a graphical object displayed on the touch sensitive screen;

determining position of each of the two user interactions with respect to the graphical object;

detecting displacement of at least one of the two user interactions; and

manipulating the graphical object based on the displacement to maintain the same position of each of the two user interactions with respect to the graphical object.

2 . The method according claim 1 , wherein the manipulating of the graphical object provides for maintaining an angle between a line segment connecting the position of two user interactions on the graphical object and an axis of the graphical object in response to the displacement.

3 . The method according to claim 1 , wherein the manipulating includes resizing of the graphical object along one axis of the graphical object, and wherein the resizing is determined by a ratio of a distance between the positions of the two user interactions along the axis of the graphical object after the displacement and a distance between the positions of the two user interactions along the axis of the graphical object before the displacement.

4 . The method according to claim 1 , wherein the manipulating includes resizing of the graphical object, and wherein the resizing is determined by a ratio of a distance between the two user interactions after the displacement and a distance between the user interactions before the displacement.

5 . The method according to claim 1 , wherein the manipulating is performed as long as the at least two user interactions maintain their presence on the graphical object.

6 . The method according to claim 1 , wherein the defined boundary encompasses the graphical object as well as a frame around the graphical object.

7 . The method according to claim 1 , wherein the presence of the at least two user interactions is detected in response to stationary positioning of the two user interactions within the defined boundary of the graphical object for a pre-defined time period.

8 . The method according to claim 1 wherein the touch sensitive screen includes at least two graphical objects and wherein a first set of user interactions is operative to manipulate a first graphical object and a second set of user interactions is operative to manipulate a second graphical object.

9 . The method according to claim 8 , wherein the first and second objects are manipulated simultaneously and independently.

10 . The method according to claim 1 , wherein the graphical object is an image.

11 . The method according to claim 1 , wherein aspect ratio of the graphical object is held constant during the manipulation.

12 . The method according to claim 1 , wherein the presence of one of the two user interactions is provided by hovering over the touch sensitive screen.

13 . The method according to claim 1 , wherein the presence of one of the two user interaction is provided by touching the touch sensitive screen.

14 . The method according to claim 1 , wherein the two user interactions are selected from a group including: fingertip, stylus, and conductive object or combinations thereof.

15 . The method according to claim 1 , wherein the manipulation does not require determination of a trajectory of the two user interactions.

16 . The method according to claim 15 wherein the manipulation does not require analysis of the trajectory.

17 . The method according to claim 1 , wherein the touch sensitive screen is a multi-touch screen.

18 . The method according to claim 1 , wherein the touch sensitive screen comprises a sensor including two orthogonal sets of parallel conductive lines forming a grid.

19 . The method according to claim 18 , wherein the sensor is transparent.

20 . A method for graphical object manipulation using a touch sensitive screen, the method comprising:

determining global coordinates of a plurality of user interactions on a touch sensitive screen, wherein the global coordinates are coordinates with respect to a global coordinate system locked on the touch sensitive screen;

detecting a presence of two user interactions within a defined boundary of a graphical object displayed on the touch sensitive screen, wherein the presence is determined from the global coordinates of the two user interactions and the global coordinates of the defined boundary of the graphical object;

defining a local coordinate system for the at least one graphical object, wherein the local coordinate system is locked on the at least one graphical object;

determining coordinates of each of the two user interactions in the local coordinate system;

detecting displacement of a position of at least one of the two user interactions; and

manipulating the at least one graphical object in response to the displacement to maintain the same coordinates of the two user interactions determined in the local coordinate system.

21 . The method according to claim 20 , wherein the manipulating includes one or more of resizing, translating and rotating the graphical object.

22 . The method according to claim 20 comprising updating the local coordinate system of the graphical object in response to the displacement.

23 . The method according to claim 20 comprising determining a transformation between the global and the local coordinate system and updating the transformation in response to the displacement.

24 . The method according to claim 23 wherein the transformation is defined based on a requirement that the coordinates of the two user interactions in the local coordinate system determined prior to the displacement is the same as the coordinates of the two user interactions in the updated local coordinate system.

25 . The method according to claim 20 , wherein the manipulating of the graphical object provides for maintaining an angle between a line segment connecting the coordinates of two user interactions on the graphical object and an axis of the local coordinate system of the graphical object in response to the displacement and manipulating.

26 . The method according to claim 20 , wherein the manipulating includes resizing of the graphical object along one axis of the local coordinate system, and wherein the resizing is determined by a ratio of a distance between the two user interactions along the axis of the local coordinate system after the displacement and a distance between the two user interactions along the axis of the local coordinate system before the displacement.

27 . The method according to claim 20 , wherein the manipulating includes resizing of the graphical object, and wherein the resizing is determined by a ratio of a distance between the two user interactions after the displacement and a distance between the user interactions before the displacement.

28 . The method according to claim 20 , wherein the manipulating is performed as long as the at least two user interactions maintain their presence on the graphical object.

29 . The method according to claim 20 , wherein the defined boundary encompasses the graphical object as well as a frame around the graphical object.

30 . The method according to claim 20 , wherein the presence of the at least two user interactions is detected in response to stationary positioning of the two user interactions within the defined boundary of the graphical object for a pre-defined time period.

31 . The method according to claim 20 , wherein the touch sensitive screen includes at least two graphical objects and wherein a first set of user interactions is operative to manipulate a first graphical object and a second set of user interactions is operative to manipulate a second graphical object.

32 . The method according to claim 31 , wherein the first and second objects are manipulated simultaneously and independently.

33 . The method according to claim 20 , wherein the graphical object is an image.

34 . The method according to claim 20 , wherein aspect ratio of the graphical object is held constant during the manipulation.

35 . The method according to claim 20 , wherein the presence of one of the two user interactions is provided by hovering over the touch sensitive screen.

36 . The method according to claim 20 , wherein the presence of one of the two user interaction is provided by touching the touch sensitive screen.

37 . The method according to claim 20 , wherein the two user interactions are selected from a group including: fingertip, stylus, and conductive object or combinations thereof.

38 . The method according to claim 20 , wherein the manipulation does not require determination of a trajectory of the two user interactions.