Systems and methods for generating visual representations of graphical data and digital document processing

• US 20050017986A1
• Filed: 10/10/2002
• Published: 01/27/2005
• Est. Priority Date: 10/13/2001
• Status: Active Grant

• Current Assignee: Artifex Software Inc.
• Original Assignee: Picsel (Research) Limited
• Inventors: Anwar, Majid, Pollock, Brian Richard
• Granted Patent: US 7,271,814 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text

Abstract

A method of blending a plurality of mutually overlapping graphical objects in a digital document processing system. The graphical objects are arranged in an ordered stack that includes at least one static object and at least one animated object. Each object has at least one associated blending parameter (e.g., transparency). The method comprises: (a) blending the content of the static objects to form at least one composite static object, taking account of the respective blending parameters of the static objects; and (b) blending the content of the animated object and the composite static object(s), taking account of the blending parameter(s) of the animated object.

Claims

1. A method of blending a plurality of mutually overlapping graphical objects in a digital document processing system, wherein said plurality of graphical objects is arranged in an ordered stack that includes at least one static object and at least one animated object, each of said objects comprising graphical content and having at least one blending parameter for at least part of the object associated therewith, the method comprising:

(a) blending the content of said static objects to form at least one composite static object, taking account of the respective blending parameters of the static objects; and

(b) blending the content of the animated object and the or each composite static object, taking account of the blending parameter (s) of the animated object.

2. The method of claim 1, further including:

(c) repeating step (b) using the previously obtained composite static object(s) formed in step (a) when the content of the animated object changes.

3. The method of claim 2, wherein current display content formed in step (b) using first animated object content is replaced by new display content formed by blending second animated object content and the previously obtained composite static object(s) formed in step (a).

4. The method of claim 2, wherein current display content formed in step (b) using first animated object content is updated by subtracting the first animated content from the current display content and adding second animated object content.

5. The method of claim 1, wherein the animated object is on top of the stack and step (a) comprises blending static objects located below an animated object in the stack to form a single composite static object, and step (b) includes blending the animated object with the single composite static object.

6. The method of claim 1, wherein the animated object is at the bottom of the stack and step (a) comprises blending static objects located above the animated object in the stack to form a single composite static object, and step (b) includes blending the animated object with the single composite static object.

7. The method of claim 1, wherein step (a) comprises blending static objects located below an animated object in the stack to form a first composite static object and blending static objects located above the animated object in the stack to form a second composite static object, and step (b) includes blending the animated object with the first and second composite static objects.

8. The method of claim 7, wherein the stack includes a plurality of animated objects, and wherein step (b) includes forming a composite static object for each group of static objects that is located either below a bottom-most animated object, above a top-most animated object or interposed between animated objects in the stack.

9. The method of claim 1, wherein step (a) comprises blending the content of all of the static objects in the stack into a single composite static object, taking account of the relative blending parameters of all of the static and animated objects in the stack, and forming a blending parameter value stencil for the or each animated object in the stack, the blending parameter value(s) of the or each stencil taking account of the blending parameter value(s) of the corresponding animated object and of any objects above the corresponding animated object in the stack, and step (b) comprises blending the content of the or each animated object with the composite static object on the basis of the corresponding blending parameter value stencil.

10. The method of claim 9, wherein the objects are blended in a display buffer, and including:

processing the objects in order from the bottom to the top of the stack by scaling the current content of the display buffer by the complement of the blending parameter value of the next object in the stack, and where the next object in the stack is a static object, scaling the content of that static object by its own blending parameter value, and adding the scaled content of that static object to the scaled content of the display buffer.

11. The method of claim 10, wherein a blending parameter value stencil for each animated object is formed in a stencil buffer, and including:

where the next object in the stack is that animated object corresponding to the stencil buffer, scaling the blending parameter value(s) of the stencil by the blending parameter value(s) of the animated object, and where the next object in the stack is above the animated object corresponding to the stencil buffer, scaling the current blending parameter value(s) of the stencil buffer by the complement of the blending parameter value(s) of that next object.

12. The method of claim 11, wherein step (b) comprises scaling the content of the animated object by the blending parameter value(s) of the corresponding stencil and adding the scaled animated object content to the composite, scaled static object content of the display buffer.

13. The method of claim 12, wherein current display content is updated by scaling new animated object content using the previously obtained blending parameter value stencil and adding the new scaled animated object content to the previously obtained composite static object.

14. The method of claim 12, wherein current display content is updated by scaling new animated object content using the previously obtained blending parameter value stencil, subtracting the current scaled animated object content from the current display content and adding the new scaled animated object content.

15. The method of claim 10, adapted for varying the value of a blending parameter of at least one animated object in an ordered stack of graphical objects in one or more steps, comprising forming first and second blending parameter stencils and first and second display buffers for the or each animated object in the stack corresponding to first and second blending parameter values or sets of blending parameter values, the blending parameter value(s) of each of said first and second stencils taking account of the blending parameter value(s) of the corresponding animated object and of any objects above the corresponding animated object in the stack and, for each step of varying the value of the blending parameter, deriving a resultant blending parameter stencil and resultant display buffer content from the first and second stencils and the first and second display buffers and the required parameter blending value for the current step, for use in said step (b).

16. The method of claim 15, wherein the first stencil, SO, and the first display buffer, DO, are created using a blending parameter value of zero and the second stencil, S0, and the second display buffer, D1, are created using a blending parameter value of 1, and wherein the resultant stencil, S, and the resultant display buffer content, D, are calculated for the required parameter blending value, t, of the current step as follows:

D=(1−

t)DO+tD1
S=(1−

t)SO+tS1.

17. A method as claimed in claim 1, wherein said at least one blending parameter of each object includes at least one alpha value representing the transparency of at least part of the object associated therewith.

18. A method as claimed in claim 1, wherein said at least one blending parameter is an achromatic blending parameter applicable to all colour channels of the object associated therewith.

19. A method as claimed in claim 1, wherein said at least one blending parameter comprises a plurality of chromatic blending parameter values, each chromatic blending parameter value being applicable to at least one colour channel of the object associated therewith.

20. A method as claimed in claim 1, including dividing said graphical objects and composite objects into a plurality of bitmap tiles of fixed, predetermined size and storing said tiles in an indexed array.

21. A method as claimed in claim 20, including selectively clipping at least one of said objects by rounding to the nearest tile size.

22. A method as claimed in claim 20, wherein current content of said graphical objects is updated by removing redundant tiles from said selected set and adding new tiles to said selected set.

23. A method as claimed in claim 20, including processing subsets of said tiles in parallel.

24. A method as claimed in claim 1 wherein said objects and content are assembled from a plurality of bitmap tiles of fixed, predetermined size.

25. A method as claimed in claim 1, wherein said graphical objects originate from at least one content source for transmission to at least one output location via a data communications network, and wherein the blending steps (a) and (b) are performed at least partially at one of the at least one of said content sources, at least one of said output locations, and at at least one intermediate location.

26. A digital document processing system adapted to implement the method of claim 1.

27. A system as claimed in claim 26, comprising:

an input mechanism for receiving an input bytestream representing source data in one of a plurality of predetermined data formats;

an interpreting mechanism for interpreting said bytestream;

a converting mechanism for converting interpreted content from said bytestream into an internal representation data format; and

a processing mechanism for processing said internal representation data so as to generate output representation data adapted to drive an output device.

28. A system as claimed in claim 27, wherein said source data defines the content and structure of a digital document, and wherein said internal representation data describes said structure in terms of generic objects defining a plurality of data types and parameters defining properties of specific instances of generic objects, separately from said content.

29. A system as claimed in claim 28, further including a library of generic object types, said internal representation data being based on the content of said library.

30. A system as claimed in claim 28, including a parsing and rendering module adapted to generate an object and parameter based representation of a specific view of at least part of said internal representation data, on the basis of a first control input to said parsing and rendering module.

31. A system as defined in claim 30, further including a shape processing module adapted to receive said object and parameter based representation of said specific view from said parsing and rendering module and to convert said object and parameter based representation into an output data format suitable for driving a particular output device.

32. A system as claimed in claim 31, wherein said shape processing module processes said objects on the basis of a boundary box defining the boundary of an object, a shape defining the actual shape of the object bounded by the boundary box, the data content of the object and the transparency of the object.

33. A system as claimed in claim 32, wherein said shape processing module is adapted to apply grey-scale anti-aliasing to the edges of said objects.

34. A system as claimed in claim 31, wherein said shape processing module has a pipeline architecture.

35. A system as claimed in claim 28, wherein said object parameters include dimensional, physical and temporal parameters.

36. A system as claimed in claim 27, wherein the system employs a chrominance/luminance-based colour model to describe colour data.

37. A system as claimed in claim 27, wherein the system is adapted for multiple parallel implementation in whole or in part for processing one or more sets of source data from one or more data sources and for generating one or more sets of output representation data.

38. A graphical user interface for a data processing system in which interactive visual displays employed by the user interface are generated by means of a digital document processing system as claimed in claim 26.

39. A data processing device incorporating a graphical user interface as claimed in claim 38.

40. (Currently amended) A hardware device for data processing and/or storage encoding a digital document processing system as claimed in claim 26.

41. A hardware device as claimed in claim 40, further including a core processor system.

42. A hardware device as claimed in claim 41, wherein said core processor is a RISC processor.

43. A data processing system including a digital document processing system as claimed in claim 26.

44. A data processing system as claimed in claim 43, wherein said data processing system comprises a portable data processing device.

45. A data processing system as claimed in claim 44, wherein said portable data processing device comprises a wireless telecommunications device.

46. A data processing system as claimed in claim 43, wherein said data processing system comprises a network user-terminal.

47. A peripheral device for use with a data processing system, including a digital document processing system as claimed in claim 26.

48. A peripheral device as claimed in claim 47, wherein said peripheral device is a visual display device.

49. A peripheral device as claimed in claim 47, wherein said peripheral device is a hardcopy output device.

50. A peripheral device as claimed in claim 47, wherein said peripheral device is an input device.

51. A peripheral device as claimed in claim 47, wherein said peripheral device is a network device.

52. A peripheral device as claimed in claim 47, wherein said peripheral device is a multi-function peripheral device