METHOD AND SYSTEM FOR INK DATA GENERATOR, INK DATA RENDERING, INK DATA MANIPULATION AND INK DATA COMMUNICATION

• US 20150371417A1
• Filed: 08/27/2015
• Published: 12/24/2015
• Est. Priority Date: 11/19/2013
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Angelov, Branimir, Petkov, Plamen
• Granted Patent: US 9,448,648 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/0383 Remote input, i.e. interface arrangements in which the signals generated by a pointing device are transmitted to a PC at a remote location, e.g. to a PC in a LAN
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/0354 with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06Q 10/101 Collaborative creation, e.g. joint development of products or services
• CPC Class Codes: G06T 11/203 Drawing of straight lines or curves
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32
• CPC Class Codes: G06V 30/347 Sampling; Contour coding; Stroke extraction

Abstract

Methods and systems are provided for generating, rendering, manipulating (e.g., slicing), and communicating stroke objects that form ink data. In a method of generating a stroke object, pen event data indicative of pen down, pen movement, and pen up events are sequentially received to generate point objects that collectively form a stroke object. The point objects serve as control points for interpolating curve segments. Further, a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts, and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the stroke object ends, are generated for the stroke object. When rendering the stroke object, a system limits display of the stroke object to a range bound by the start and end parameters, as opposed to displaying the entire stroke object.

Claims

1. A method of generating ink data in a device including a position input sensor, the ink data including stroke objects that are vector data configured to reproduce paths formed by operating a pointer, the method comprising:

sequentially receiving pen event data detected by the input sensor, the pen event data being indicative of pen down, pen movement, and pen up events;

sequentially generating point objects based on coordinate values included in the received pen event data, wherein the point objects serve as control points for interpolating curve segments according to a defined curve interpolation algorithm to form a stroke object;

generating a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the stroke object ends; and

outputting the start parameter and the end parameter as well as the point objects as part of the stroke object in a defined format.

2. The method of claim 1, wherein the defined curve interpolation algorithm is a local-control algorithm in which a value of i-th point object impacts a limited number of curve segments adjacent to the i-th point object.

3. The method of claim 2, wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm.

4. The method of claim 3, wherein the start point indicates an internal division point between two end points of the starting curve segment where the display starts and the end point indicates an internal division point between two end points of the ending curve segment where the display ends.

5. The method of claim 4, further comprising:

generating a point object to serve as an additional control point on an initial point object of the stroke object to form the starting curve segment, wherein generating the point object to serve as an additional control point involves duplicating a value of the initial point object.

6. The method of claim 4, further comprising:

determining whether smoothing is to be applied; and

if it is determined that the smoothing is to be applied, generating one or more point objects to serve as additional control points on a last point object to form the end curve segment by duplicating a last value of the point object to fill the lag between a smoothed coordinate of the last point object and an original coordinate of the last point object.

7. The method of claim 1, wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm, and the method further comprises one or both of:

duplicating a value of an initial point object to create a starting control point to fix a shape of curve of the starting curve segment; and

duplicating a value of an end point object to create an ending control point to fix a shape of curve of the ending curve segment.

8. A method of rendering a stroke object of ink data on a device including an input sensor and a graphic processor, the ink data including stroke objects that are vector data configured to reproduce paths hand-drawn by a user, the method comprising:

extracting point objects from a stroke object, and interpolating plurality of curve segments using the extracted point objects as control points according to a defined curve interpolation algorithm to reconstruct a stroke object path;

extracting a start parameter indicative of a start point within a starting curve segment of the curve segments and an end parameter indicative of an end point within an ending curve segment of the curve segments; and

limiting rendering or display of the starting curve segment and the ending curve segment of the stroke object to a range indicated by the start parameter and the end parameter respectively.

9. The method of claim 8, wherein the defined curve interpolation algorithm is a local-control algorithm in which a value of i-th point object impacts a limited number of curve segments adjacent to the i-th point object that is less than a total number of curve segments included in the stroke object.

10. The method of claim 9, wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm or a Poly-Bezier Curve.

11. A method of manipulating pre-existing ink data in a memory of a device including an input sensor to generate new ink data, comprising:

receiving input information including coordinates data from the input sensor;

receiving manipulation information indicating whether the input information is configured to transform the pre-existing stroke object of the ink data;

selecting a part or a full of a target stroke object to be transformed if a stroke path formed by the coordinates data included in the input information intersects the target stroke object; and

when the manipulation information indicates that the input information is configured to slice the pre-existing stroke object, slicing the selected target stroke object at an intersected section to generate two slice objects from the selected target stroke object, wherein

the two slice objects provide modification to divide the pre-existing stroke object into two new stroke objects; and

each of the two slice objects includes a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the slice object starts and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the slice object ends when the two new stroke objects generated by finalizing the two slice object are rendered.

12. The method of claim 11, wherein each of the two slice objects includes:

an index of a point object in the pre-existing stroke object indicating a start point object of the slice object, wherein the index is a control point index used to maintain the shape of the starting curve segment before and after the manipulation; and

an index of a point object in the pre-existing stroke object indicating an end point object of the slice object, wherein the index is a control point index used to maintain the shape of the ending curve segment before and after the manipulation.

13. The method of claim 12, wherein said slicing step includes:

determining a cross-point at which the selected target stroke object is sliced;

determining a new end point within an ending curve segment of a first slice object based on the determined cross-point; and

determining a new start point within a starting curve segment of a second slice object based on the determined cross-point.

14. The method of claim 13, wherein

the input information configured to slice a pre-existing stroke object is a stroke object having a width such that said stroke object intersects the selected target stroke at a first cross-point and a second cross-point;

the step of determining the new end point of the first slice object includes determining the first cross-point as the new end point; and

the step of determining the new start point of the second slice object includes determining the second cross-point as the new start point.

15. The method of claim 14, wherein the slicing operation is used in an eraser application to erase a portion of the pre-existing stroke having the width.

16. The method of claim 15, further comprising:

determining whether the ink data including the pre-existing stroke is shared by a remote computer; and

if it is determined that the ink data is shared by the remote computer, transmitting to the remote computer the information to slice the pre-existing stroke object existent in a memory of the remote computer to two new stroke objects in a message.

17. The method of claim 16, wherein the information to slice is selected from a group consisting of:

a slicing stroke object used for the slicing;

two slice objects resulting from the slicing;

a hole segment object resulting from the slicing; and

two new stroke objects generated from the two slice objects.

18. The method of claim 16, wherein in case the remote computer is incapable of carrying out the slicing operation, transmitting to the remote computer the two stroke objects resulting from finalizing the two slice objects.