Dynamic selection of anti-aliasing procedures

• US 20040227771A1
• Filed: 05/16/2003
• Published: 11/18/2004
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Adobe Inc., Deere & Company
• Original Assignee: Deere & Company
• Inventors: Arnold, R. David, Dowling, Terence S.
• Granted Patent: US 7,002,597 B2
• Time in Patent Office: Days
• US Class Current: 345/611
• CPC Class Codes: G06F 40/109 Font handling; Temporal or kinetic typography
• CPC Class Codes: G06T 11/203 Drawing of straight lines or curves

Abstract

Methods, apparatus, including computer program products, and systems implement and use techniques for rendering glyphs. A plurality of glyphs to be rendered are received. For each glyph, an anti-aliasing procedure is selected to render the glyph. The anti-aliasing procedure is selected from a first anti-aliasing procedure and one or more alternative anti- aliasing procedures. The anti-aliasing procedure for each glyph is selected based on the glyph.

Claims

1. A computer-implemented method, comprising:

receiving a plurality of glyphs to be rendered; and

for each glyph, selecting an anti-aliasing procedure to render the glyph based on the glyph, the anti-aliasing procedure being selected from a first anti-aliasing procedure and one or more alternative anti-aliasing procedures.

2. The method of claim 1, wherein selecting an anti-aliasing procedure includes:

partially rendering a glyph using the first anti-aliasing procedure;

evaluating one or more characteristics of the glyph based on the partial rendering; and

selecting an anti-aliasing procedure from the first anti-aliasing procedure and the one or more alternative anti-aliasing procedures based on the evaluating.

3. The method of claim 2, further comprising:

rendering the glyph based on the selected anti-aliasing procedure.

4. The method of claim 3, wherein rendering the glyph includes:

discarding the partial rendering; and

rendering the glyph using one of the alternative anti-aliasing procedures.

5. The method of claim 3, wherein rendering the glyph includes:

selecting one of the alternative anti-aliasing procedures; and

rendering the glyph using the selected alternative anti-aliasing procedure and the partial rendering of the glyph from the first anti-aliasing procedure.

6. The method of claim 2, wherein partially rendering a glyph includes calculating a hinted outline of the glyph.

7. The method of claim 2, wherein:

evaluating one or more characteristics of the glyph includes determining a complexity of the glyph and comparing the complexity to a predetermined threshold value.

8. The method of claim 7, wherein:

the glyph is to be rendered at a size; and

the complexity is measured as a cumulative horizontal length of the glyph path divided by the size.

9. The method of claim 2, wherein evaluating one or more characteristics of the glyph includes determining whether one or more specified hint instructions were used to partially render the glyph.

10. The method of claim 1, wherein the first anti-aliasing procedure is an anisotropic anti- aliasing procedure.

11. The method of claim 1, wherein the glyph is included in a TrueType font.

12. A computer-implemented method for rendering a plurality of glyphs, comprising:

partially rendering each glyph in a plurality of glyphs using a first anti-aliasing procedure;

determining on a glyph-by-glyph basis a preferred anti-aliasing procedure for each glyph based on the partial rendering of the glyph; and

rendering each glyph using the preferred anti-aliasing procedure determined for the glyph.

13. The method of claim 12, wherein determining a preferred anti-aliasing procedure for a glyph includes:

evaluating one or more characteristics of the glyph based on the partial rendering; and

determining a preferred anti-aliasing procedure from the first anti-aliasing procedure and one or more alternative anti-aliasing procedures based on the evaluating.

14. The method of claim 13, wherein:

evaluating one or more characteristics of the glyph includes determining a complexity of the glyph and comparing the complexity to a predetermined threshold value.

15. The method of claim 14, wherein:

the glyph is to be rendered at a size; and

the complexity is measured as a cumulative horizontal length of the glyph path divided by the size.

16. The method of claim 13, wherein evaluating one or more characteristics of the glyph includes determining whether one or more specified hint instructions were used to partially render the glyph.

17. The method of claim 12, wherein rendering a glyph includes:

discarding the partial rendering; and

rendering the glyph using one of the alternative anti-aliasing procedures.

18. The method of claim 12, wherein rendering a glyph includes:

determining the preferred anti-aliasing procedure to be one of the alternative anti- aliasing procedures; and

rendering the glyph using the preferred alternative anti-aliasing procedure and the partial rendering of the glyph from the first anti-aliasing procedure.

19. The method of claim 12, wherein partially rendering a glyph includes calculating a hinted outline of the glyph.

20. The method of claim 12, wherein the first anti-aliasing procedure is an anisotropic anti-aliasing procedure.

21. The method of claim 12, wherein the glyph is included in a TrueType font.

22. A computer program product, tangibly stored on a computer-readable medium, comprising instructions operable to cause a programmable processor to:

receive a plurality of glyphs to be rendered; and

for each glyph, select an anti-aliasing procedure to render the glyph based on the glyph, the anti-aliasing procedure being selected from a first anti-aliasing procedure and one or more alternative anti-aliasing procedures.

23. The computer program product of claim 22, wherein instructions operable to select an anti-aliasing procedure include instructions operable to:

partially render a glyph using the first anti-aliasing procedure;

evaluate one or more characteristics of the glyph based on the partial rendering; and

select an anti-aliasing procedure from the first anti-aliasing procedure and the one or more alternative anti-aliasing procedures based on the evaluating.

24. The computer program product of claim 23, further comprising instructions operable to:

render the glyph based on the selected anti-aliasing procedure.

25. The computer program product of claim 24, wherein instructions operable to render the glyph include instructions operable to:

discard the partial rendering; and

render the glyph using one of the alternative anti-aliasing procedures.

26. The computer program product of claim 24, wherein instructions operable to render the glyph include instructions operable to:

select one of the alternative anti-aliasing procedures; and

render the glyph using the selected alternative anti-aliasing procedure and the partial rendering of the glyph from the first anti-aliasing procedure.

27. The computer program product of claim 23, wherein instructions operable to partially render a glyph include instructions operable to calculate a hinted outline of the glyph.

28. The computer program product of claim 23, wherein:

instructions operable to evaluate one or more characteristics of the glyph include instructions operable to determine a complexity of the glyph and compare the complexity to a predetermined threshold value.

29. The computer program product of claim 28, wherein:

the glyph is to be rendered at a size; and

the complexity is measured as a cumulative horizontal length of the glyph path divided by the size.

30. The computer program product of claim 23, wherein instructions operable to evaluate one or more characteristics of the glyph include instructions operable to determine whether one or more specified hint instructions were used to partially render the glyph.

31. The computer program product of claim 22, wherein the first anti-aliasing procedure is an anisotropic anti-aliasing procedure.

32. The computer program product of claim 22, wherein the glyph is included in a TrueType font.

33. A computer program product, tangibly stored on a computer-readable medium, for rendering a plurality of glyphs, comprising instructions operable to cause a programmable processorto:

partially render each glyph in a plurality of glyphs using a first anti-aliasing procedure;

determine on a glyph-by-glyph basis a preferred anti-aliasing procedure for each glyph based on the partial rendering of the glyph; and

render each glyph using the preferred anti-aliasing procedure determined for the glyph.

34. The computer program product of claim 33, wherein instructions operable to determine a preferred anti-aliasing procedure for a glyph include instructions operable to:

evaluate one or more characteristics of the glyph based on the partial rendering; and

determine a preferred anti-aliasing procedure from the first anti-aliasing procedure and one or more alternative anti-aliasing procedures based on the evaluation.

35. The computer program product of claim 34, wherein instructions operable to evaluate one or more characteristics of the glyph include instructions operable to determine a complexity of the glyph and compare the complexity to a predetermined threshold value.

36. The computer program product of claim 35, wherein:

the glyph is to be rendered at a size; and

the complexity is measured as a cumulative horizontal length of the glyph path divided by the size.

37. The computer program product of claim 34, wherein instructions operable to evaluate one or more characteristics of the glyph include instructions operable to determine whether one or more specified hint instructions were used to partially render the glyph.

38. The computer program product of claim 33, wherein instructions operable to render a glyph include instructions operable to:

discard the partial rendering; and

render the glyph using one of the alternative anti-aliasing procedures.

39. The computer program product of claim 33, wherein instructions operable to render a glyph include instructions operable to:

determine the preferred anti-aliasing procedure to be one of the alternative anti- aliasing procedures; and

render the glyph using the preferred alternative anti-aliasing procedure and the partial rendering of the glyph from the first anti-aliasing procedure.

40. The computer program product of claim 33, wherein instructions operable to partially render a glyph include instructions operable to calculate a hinted outline of the glyph.

41. The computer program product of claim 33, wherein the first anti-aliasing procedure is an anisotropic anti-aliasing procedure.

42. The computer program product of claim 33, wherein the glyph is included in a TrueType font.