US5814801A
Expired / Lapsed
US
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Maxicode data extraction using spatial domain features exclusive of fourier type domain transfer processing
Assignee: Symbol Technologies LLC
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Filing: 1996-11-01
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Granted: 1998-09-29
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Expires: 2016-11-01
Abstract
Abstract Prior methods of reading MaxiCode dataforms have been subject to reduced resolution image scaling and processing and speed constraints of Fourier transform computations. Described spatial domain data extraction methods provide bull's eye center location by T-sequence pixel pattern analysis, axis identification by moment analysis of data cell pairs, and integral width square wave analysis of illumination transitions to avoid reading-line cell fragmentation. The center and top of a MaxiCode are identified in high-resolution pixel data, without scaling reduction or Fourier type frequency domain processing. Data is extracted serially from rows of data cells by sampling along lines of pixels aligned by fragmentation analysis so as to traverse complete rows of data cells. Dynamic thresholding accurately defines illumination value transitions between adjacent linear groups of data cells, each group consisting of one or more data cells of the same reflectivity. Application of disclosed methods to other types of dataforms is described.
Inventors
- 👤 Ynjiun P. Wang
- 👤 Angi Ye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:46
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/14; G06K7/1404; G06K7/1408; G06K7/1421; G06K19/00; G06K19/06; G06K19/06009; G06K19/06037; G06K19/06046; G06K19/06168; G06K7/1439; G06K7/1456; G06K7/146; G06K7/1486; G06K7/1491
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
131 words
A method of extracting data by processing a MaxiCode type of dataform entirely in the spatial domain exclusive of Fourier type domain transfer processing, said dataform including a pattern of similarly aligned hexagonal data cells, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of illumination reflected from said hexagonal data cells; (b) determining the orientation of a plurality of said hexagonal data cells positioned in a row in side-to-side straight line alignment; (c) extracting data from said plurality of hexagonal data cells by sampling said pixel data along a line traversing each data cell of said plurality; and (d) processing said extracted data to recover information encoded in said dataform, independently of use of Fourier type processing in any step of said method.
Claim 2
Independent Claim
131 words
A method of extracting data by processing a MaxiCode type of dataform entirely in the spatial domain exclusive of Fourier type domain transfer processing, said dataform including a pattern of similarly aligned hexagonal data cells, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of illumination reflected from said hexagonal data cells; (b) determining the orientation of a plurality of said hexagonal data cells positioned in a row in side-to-side straight line alignment; (c) extracting data from said plurality of hexagonal data cells by sampling said pixel data along a line traversing each data cell of said plurality; and (d) processing said extracted data to recover information encoded in said dataform, independently of use of Fourier type processing in any step of said method.
Claim 3
Dependent Claim
47 words
A method as in claim 1, wherein in step (b) said orientation is determined by moment analysis of a portion of said pixel data, said orientation corresponding to the derived moment of two hexagonal data cells of said plurality which are contiguous and of the same reflectivity.
Claim 4
Dependent Claim
53 words
A method as in claim 1, wherein in step (b) said row of hexagonal data cells is aligned with a reference line defined by sampling said pixel data to identify a traversal line of pixel data characterized by illumination value transitions spaced along said traversal line at integral multiples of data cell width.
Claim 5
Independent Claim
133 words
A method of extracting data from a MaxiCode type of dataform, having a pattern of similarly aligned hexagonal data cells of differing reflectivity values, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of illumination reflected from said hexagonal data cells; (b) determining the orientation of a plurality of said hexagonal data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from said plurality of hexagonal data cells along a line traversing each data cell of said plurality; and (d) extracting data from said image data sampled in step (c) by determining spacings of illumination value transitions between data cell groups along said line, each said data cell group consisting of one or more contiguous data cells of similar reflectivity value.
Claim 6
Independent Claim
133 words
A method of extracting data from a MaxiCode type of dataform, having a pattern of similarly aligned hexagonal data cells of differing reflectivity values, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of illumination reflected from said hexagonal data cells; (b) determining the orientation of a plurality of said hexagonal data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from said plurality of hexagonal data cells along a line traversing each data cell of said plurality; and (d) extracting data from said image data sampled in step (c) by determining spacings of illumination value transitions between data cell groups along said line, each said data cell group consisting of one or more contiguous data cells of similar reflectivity value.
Claim 7
Dependent Claim
47 words
A method as in claim 4, wherein in step (b) said orientation is determined by moment analysis of a portion of said pixel data, said orientation corresponding to the derived moment of two hexagonal data cells of said plurality which are contiguous and of the same reflectivity.
Claim 8
Dependent Claim
53 words
A method as in claim 4, wherein in step (b) said row of hexagonal data cells is aligned with a reference line defined by sampling said pixel data to identify a traversal line of pixel data characterized by illumination value transitions spaced along said traversal line at integral multiples of data cell width.
Claim 9
Independent Claim
121 words
A method of extracting data from a dataform having a pattern of rows of similarly aligned lighter and darker data cells of a regular polygon shape, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of reflected images of said data cells; (b) determining, by moment analysis of a portion of said pixel data, the orientation of a normal traversal line having an alignment normal to sides of a series of said data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from a plurality of said data cells along a sampling line traversing each data cell of said plurality; and (d) extracting data from said sampled image data.
Claim 10
Independent Claim
121 words
A method of extracting data from a dataform having a pattern of rows of similarly aligned lighter and darker data cells of a regular polygon shape, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of reflected images of said data cells; (b) determining, by moment analysis of a portion of said pixel data, the orientation of a normal traversal line having an alignment normal to sides of a series of said data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from a plurality of said data cells along a sampling line traversing each data cell of said plurality; and (d) extracting data from said sampled image data.
Claim 11
Dependent Claim
15 words
A method as in claim 7, wherein said dataform is a MaxiCode type of dataform.
Claim 12
Dependent Claim
28 words
A method as in claim 7, wherein step (b) comprises determining said orientation as the derived moment of two data cells which are contiguous and of similar reflectivity.
Claim 13
Dependent Claim
28 words
A method as in claim 7, wherein step (b) comprises determining said orientation as the derived moment of a group of data cells in side-to-side straight line alignment.
Claim 14
Dependent Claim
49 words
A method as in claim 7, wherein step (c) comprises sampling image data along a sampling line having one of the following orientations: aligned with and parallel to said normal traversal line; aligned with said normal traversal line at an angular separation of an integral multiple of 60 degrees.
Claim 15
Dependent Claim
44 words
A method as in claim 7, wherein step (d) comprises extracting data by determining spacings of illumination value transitions between data cell groups along said sampling line, each said data cell group consisting of one or more contiguous data cells of similar reflectivity value.
Claim 16
Independent Claim
126 words
A method of extracting data from a dataform having a pattern of rows of similarly aligned lighter and darker data cells of a regular polygon shape, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of reflected images of said data cells; (b) determining, by the presence of illumination value transitions spaced at integral multiples of data cell width, the orientation of a normal traversal line having an alignment normal to sides of a series of said data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from a plurality of said data cells along a sampling line traversing each data cell of said plurality; and (d) extracting data from said sampled image data.
Claim 17
Independent Claim
126 words
A method of extracting data from a dataform having a pattern of rows of similarly aligned lighter and darker data cells of a regular polygon shape, comprising the steps of: (a) providing pixel data for an image area, said pixel data representative of reflected images of said data cells; (b) determining, by the presence of illumination value transitions spaced at integral multiples of data cell width, the orientation of a normal traversal line having an alignment normal to sides of a series of said data cells positioned in a row in side-to-side straight line alignment; (c) sampling image data from a plurality of said data cells along a sampling line traversing each data cell of said plurality; and (d) extracting data from said sampled image data.
Claim 18
Dependent Claim
15 words
A method as in claim 13, wherein said dataform is a MaxiCode type of dataform.
Claim 19
Dependent Claim
49 words
A method as in claim 13, wherein step (c) comprises sampling image data along a sampling line having one of the following orientations: aligned with and parallel to said normal traversal line; aligned with said normal traversal line at an angular separation of an integral multiple of 60 degrees.
Claim 20
Dependent Claim
44 words
A method as in claim 13, wherein step (d) comprises extracting data by determining spacings of illumination value transitions between data cell groups along said sampling line, each said data cell group consisting of one or more contiguous data cells of similar reflectivity value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-28 | 2002-03-30 | 2002-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-28 | 2006-03-30 | 2006-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-28 | 2010-03-30 | 2010-09-29 | $7700.00 | Window Closed / Lapsed |