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US5878164A Expired / Lapsed US ⏱️ 0.0 years remaining

Interleaved segmental method for handwriting recognition

Assignee: Nokia of America Corp
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Filing: 1997-10-08
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Granted: 1999-03-02
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Expires: 2017-10-08
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Abstract

Abstract A method of handwriting recognition is provided that combines the efficiency of a point oriented system and the shape information of a segment oriented system in an HMM based handwriting recognition system. The partial segmentation hypotheses obtained using the point oriented features in a conventional Viterbi search are augmented with scores based on segmental shape measurements made on the hypothesized segments. In addition, a method for segmentation of a handwriting sample is accomplished by incorporating a feature to distinguish between continuous and not continuous strokes and influencing the indicated hypothesis score by adding a penalty to the contraindicated hypothesis score.

Inventors

  • 👤 Michael Kenneth Brown
  • 👤 Jianying Hu
  • 👤 William Turin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-10 01:14
CPC Classifications
G; G06; G06V; G06V30/00; G06V30/10; G06V30/22; G06V30/226; G06V30/2268; G10; G10L; G10L15/00; G10L15/08; G10L15/18

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 98 words
An improved method for performing handwriting recognition of a handwriting sample represented by a signal sequence, utilizing one or more point oriented feature signals to hypothesize a segment of said handwriting sample giving rise to a point oriented hypotheses score wherein the improvement comprises the steps of: generating one or more segmental feature signals of said segment of said handwriting sample giving rise to a segmental hypothesis score; augmenting said point oriented hypothesis score with a segmental matching score computed using said segmental hypothesis score; and recognizing said handwriting sample based on said augmented point oriented hypothesis score.
Claim 2
Dependent Claim 98 words
An improved method for performing handwriting recognition of a handwriting sample represented by a signal sequence, utilizing one or more point oriented feature signals to hypothesize a segment of said handwriting sample giving rise to a point oriented hypotheses score wherein the improvement comprises the steps of: generating one or more segmental feature signals of said segment of said handwriting sample giving rise to a segmental hypothesis score; augmenting said point oriented hypothesis score with a segmental matching score computed using said segmental hypothesis score; and recognizing said handwriting sample based on said augmented point oriented hypothesis score.
Claim 3
Dependent Claim 20 words
A method according to claim 1 wherein said handwriting recognition system is a Hidden Markov Model based handwriting recognition system.
Claim 4
Dependent Claim 22 words
A method according to claim 1 wherein one of said segmental feature signals is based on an inter-segmental distance measure correlation metric.
Claim 5
Dependent Claim 24 words
A method according to claim 3 further comprising the step of: preprocessing said handwriting sample so that it contains a predetermined number of points.
Claim 6
Dependent Claim 307 words
An improved method for recognizing a handwriting sample on the basis of a set of alternative hypothesis scores, said alternative hypothesis scores being accumulated at each of a set of selected hypothesis scoring points falling within said handwriting sample, each alternative hypothesis score of said set of alternative hypothesis scores representing a likelihood indication of an alternate model of said handwriting sample, said handwriting sample having one or more pen-up instances, each pen-up instance having associated therewith a spatial distance between a pen-lift point and a pen down point, said set of selected hypothesis scoring points including said pen-lift points and said pen down points, the improvement comprising the steps of: detecting each of said pen-up instances within said handwriting sample; calculating said spatial distance associated with each of said pen-up instances, respectively; associating with each of said pen-up instances a predetermined gap feature signal indicative of whether said spatial distances are at least equal to, or less than, a predetermined gap threshold spatial distance value; adjusting said set of accumulated hypothesis scores by adding a predetermined penalty to each of said accumulated hypothesis scores of said set of alternative hypothesis scores corresponding to said pen down point, indicating a model of said handwriting sample continuous between said pen lift point and said pen down point, where said predetermined gap feature signal indicates a spatial distance equal to or greater than said threshold value and by adding a predetermined penalty to each of said accumulated hypothesis scores of said set of alternative hypothesis scores corresponding to said pen down point, indicating a model of said handwriting sample not continuous between said pen lift point and said pen down point, where said predetermined gap feature signal indicates a spatial distance less than said gap threshold value; and recognizing said handwriting sample based on said adjusted alternative hypothesis scores.
Claim 7
Dependent Claim 307 words
An improved method for recognizing a handwriting sample on the basis of a set of alternative hypothesis scores, said alternative hypothesis scores being accumulated at each of a set of selected hypothesis scoring points falling within said handwriting sample, each alternative hypothesis score of said set of alternative hypothesis scores representing a likelihood indication of an alternate model of said handwriting sample, said handwriting sample having one or more pen-up instances, each pen-up instance having associated therewith a spatial distance between a pen-lift point and a pen down point, said set of selected hypothesis scoring points including said pen-lift points and said pen down points, the improvement comprising the steps of: detecting each of said pen-up instances within said handwriting sample; calculating said spatial distance associated with each of said pen-up instances, respectively; associating with each of said pen-up instances a predetermined gap feature signal indicative of whether said spatial distances are at least equal to, or less than, a predetermined gap threshold spatial distance value; adjusting said set of accumulated hypothesis scores by adding a predetermined penalty to each of said accumulated hypothesis scores of said set of alternative hypothesis scores corresponding to said pen down point, indicating a model of said handwriting sample continuous between said pen lift point and said pen down point, where said predetermined gap feature signal indicates a spatial distance equal to or greater than said threshold value and by adding a predetermined penalty to each of said accumulated hypothesis scores of said set of alternative hypothesis scores corresponding to said pen down point, indicating a model of said handwriting sample not continuous between said pen lift point and said pen down point, where said predetermined gap feature signal indicates a spatial distance less than said gap threshold value; and recognizing said handwriting sample based on said adjusted alternative hypothesis scores.
Claim 8
Dependent Claim 17 words
A method according to claim 5 wherein said predetermined gap feature signal is a binary feature signal.
Claim 9
Dependent Claim 20 words
A method according to claim 5 wherein said handwriting recognition system is a Hidden Markov Model based handwriting recognition system.
Claim 10
Independent Claim 96 words
An apparatus for performing handwriting recognition of a handwriting sample represented by a signal sequence, utilizing point oriented feature signals to hypothesize a segment of said handwriting sample giving rise to a point oriented hypothesis score, the improvement comprising: means for generating one or more segmental feature signals of said segment of said handwriting sample giving rise to a segmental hypothesis score; means for augmenting said point oriented hypothesis score with a segmental matching score computed using said segmental hypothesis score; and means for recognizing said handwriting sample based on said augmented point oriented hypothesis score.
Claim 11
Independent Claim 96 words
An apparatus for performing handwriting recognition of a handwriting sample represented by a signal sequence, utilizing point oriented feature signals to hypothesize a segment of said handwriting sample giving rise to a point oriented hypothesis score, the improvement comprising: means for generating one or more segmental feature signals of said segment of said handwriting sample giving rise to a segmental hypothesis score; means for augmenting said point oriented hypothesis score with a segmental matching score computed using said segmental hypothesis score; and means for recognizing said handwriting sample based on said augmented point oriented hypothesis score.
Claim 12
Independent Claim 137 words
A method for performing handwriting recognition of a handwriting sample comprising a string of interconnected symbols represented by a signal sequence, comprising the steps of: utilizing one or more point oriented feature signals to hypothesize one or more segmentations of said string of interconnected symbols, each of said hypothesized segmentations having associated therewith a point oriented hypothesis score; generating one or more segmental feature signals of each of said hypothesized segmentations giving rise to a segmental hypothesis score for each of said hypothesized segmentations; respectively adding to said point oriented hypothesis score of each of said hypothesized segmentations a segmental matching score computed using said segmental hypothesis score of each of said hypothesized segmentations, resulting in an augmented hypothesis score for each of said hypothesized segments; and recognizing said handwriting sample based on said augmented hypothesis score.
Claim 13
Independent Claim 137 words
A method for performing handwriting recognition of a handwriting sample comprising a string of interconnected symbols represented by a signal sequence, comprising the steps of: utilizing one or more point oriented feature signals to hypothesize one or more segmentations of said string of interconnected symbols, each of said hypothesized segmentations having associated therewith a point oriented hypothesis score; generating one or more segmental feature signals of each of said hypothesized segmentations giving rise to a segmental hypothesis score for each of said hypothesized segmentations; respectively adding to said point oriented hypothesis score of each of said hypothesized segmentations a segmental matching score computed using said segmental hypothesis score of each of said hypothesized segmentations, resulting in an augmented hypothesis score for each of said hypothesized segments; and recognizing said handwriting sample based on said augmented hypothesis score.
Claim 14
Independent Claim 141 words
An apparatus for performing handwriting recognition of a handwriting sample comprising a string of interconnected symbols represented by a signal sequence, comprising: means for hypothesizing one or more segmentations of said string of interconnected symbols utilizing one or more point oriented feature signals and generating a point oriented hypothesis score for each of said hypothesized segmentations; means for generating one or more segmental feature signals of each of said hypothesized segmentations giving rise to a segmental hypothesis score for each of said hypothesized segments; means for respectively adding to said point oriented hypothesis score for each of said hypothesized segmentations a segmental matching score computed using said segmental hypothesis score for each of said hypothesized segmentations resulting in an augmented hypothesis score for each of said hypothesized segmentations; and means for recognizing said handwriting sample based on said augmented hypothesis score.
Claim 15
Independent Claim 141 words
An apparatus for performing handwriting recognition of a handwriting sample comprising a string of interconnected symbols represented by a signal sequence, comprising: means for hypothesizing one or more segmentations of said string of interconnected symbols utilizing one or more point oriented feature signals and generating a point oriented hypothesis score for each of said hypothesized segmentations; means for generating one or more segmental feature signals of each of said hypothesized segmentations giving rise to a segmental hypothesis score for each of said hypothesized segments; means for respectively adding to said point oriented hypothesis score for each of said hypothesized segmentations a segmental matching score computed using said segmental hypothesis score for each of said hypothesized segmentations resulting in an augmented hypothesis score for each of said hypothesized segmentations; and means for recognizing said handwriting sample based on said augmented hypothesis score.

References Cited (Backward Citations)

US4933977A Cited
US5129012A Cited
US5038382A Cited
US5029223A Cited
US5121441A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-03-01 2002-08-31 2003-03-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-03-01 2006-08-31 2007-03-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-03-01 2010-08-31 2011-03-02 $7700.00 Window Closed / Lapsed

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