US5640465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for on-line tiled thresholding in scanners based on prescan
Assignee: Individual
•
Filing: 1995-12-04
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Granted: 1997-06-17
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Expires: 2015-12-04
Abstract
Abstract A scanner system comprises an optical line detector for linewise, optical scanning of an original for generating a data signal in response to the grey-level received by the detector from points along a respective line. The points are sorted with associated grey-level values in groups in response to their positional origin on the original. The individual threshold values for the grey-level values are determined statistically for a plurality of zones on the original in response to the frequency of respective grey-level values in the respective zone. The threshold values of respective zones are stored in a store. The original is re-entered by linewise, optical scanning, and the data signal generated by the scanning and representing grey-levels in points along respective, entered lines is compared in a comparator with a threshold value calculated for the point concerned, and in response to this a binary, electric representation of the original is generated.
Inventors
- 👤 Asbjorn Smitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:28
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/403
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
224 words
A method of scanning data information from an original and converting said data information to a digital representation of the original, the method comprising the steps of: (a) scanning the original by linewise, optical scanning to produce a data signal representing grey-level values of points along lines of the original; (b) dividing the original into a plurality of zones, each zone in the plurality of zones including a plurality of pixels, each pixel in the plurality of pixels having a corresponding grey-level value determined from segments of the lines which have been optically scanned during scanning, said segments being positioned in a parallel side by side relationship; (c) calculating for each zone a statistical distribution by registering a frequency of occurrence of the grey-level values received from the plurality of pixels during the scanning; (d) determining a fixed threshold value for each zone in response to the statistical distribution of the grey-level values, said determination of the fixed threshold value starting prior to termination of the prescanning; (e) storing the fixed threshold value of each zone; (f) comparing a plurality of the grey-level values in one of the plurality of zones to the fixed threshold value of the one zone; (g) generating binary values in response to said comparison; and (h) generating an electric representation of the original in response to the binary values.
Claim 2
Independent Claim
224 words
A method of scanning data information from an original and converting said data information to a digital representation of the original, the method comprising the steps of: (a) scanning the original by linewise, optical scanning to produce a data signal representing grey-level values of points along lines of the original; (b) dividing the original into a plurality of zones, each zone in the plurality of zones including a plurality of pixels, each pixel in the plurality of pixels having a corresponding grey-level value determined from segments of the lines which have been optically scanned during scanning, said segments being positioned in a parallel side by side relationship; (c) calculating for each zone a statistical distribution by registering a frequency of occurrence of the grey-level values received from the plurality of pixels during the scanning; (d) determining a fixed threshold value for each zone in response to the statistical distribution of the grey-level values, said determination of the fixed threshold value starting prior to termination of the prescanning; (e) storing the fixed threshold value of each zone; (f) comparing a plurality of the grey-level values in one of the plurality of zones to the fixed threshold value of the one zone; (g) generating binary values in response to said comparison; and (h) generating an electric representation of the original in response to the binary values.
Claim 3
Dependent Claim
22 words
The method according to claim 1 wherein determination of the fixed threshold value of each zone is made by prescanning the original.
Claim 4
Dependent Claim
43 words
The method according to claim 1 further comprising the step of corresponding one zone with the fixed threshold value for that zone such that each zone represents a rectangular area on the original which is divided into line segments disposed side by side.
Claim 5
Dependent Claim
71 words
The method according to claim 1 further comprising the step of comparing the grey-level values of the zone to a further threshold value of the zone when a first comparison point is positioned centrally in the zone, said further threshold value corresponding to an interpolation between the fixed threshold values of several adjacent zones when a second comparison point is positioned in a rim of the zone facing said adjacent zones.
Claim 6
Independent Claim
218 words
A method of scanning an original comprising the steps of: (a) scanning the original by linewise, optical scanning to provide a first data signal representing grey-level values of points along lines of the original; (b) dividing the original into a plurality of zones, each zone in the plurality of zones comprising pixels from segments of the lines which have been optically scanned during scanning, said segments being positioned in a parallel side by side relationship; (c) calculating for each zone a statistical distribution by registering a frequency of occurrence of the grey-level values received during the scanning; (d) determining a fixed threshold value for each zone in response to the statistical distribution of the grey-level values, said determination of the fixed threshold value starting prior to the termination of the scanning; (e) storing the fixed threshold value of each zone; (f) scanning the original a second time by linewise, optical scanning to produce a second data signal representing grey-level values of the points along the lines of the original; (g) comparing the grey-level values of the second data signal in one of the plurality of zones to the fixed threshold value of the zone; (h) generating binary values in response to said comparison; and (i) generating an electric representation for the original in response to the binary values.
Claim 7
Independent Claim
218 words
A method of scanning an original comprising the steps of: (a) scanning the original by linewise, optical scanning to provide a first data signal representing grey-level values of points along lines of the original; (b) dividing the original into a plurality of zones, each zone in the plurality of zones comprising pixels from segments of the lines which have been optically scanned during scanning, said segments being positioned in a parallel side by side relationship; (c) calculating for each zone a statistical distribution by registering a frequency of occurrence of the grey-level values received during the scanning; (d) determining a fixed threshold value for each zone in response to the statistical distribution of the grey-level values, said determination of the fixed threshold value starting prior to the termination of the scanning; (e) storing the fixed threshold value of each zone; (f) scanning the original a second time by linewise, optical scanning to produce a second data signal representing grey-level values of the points along the lines of the original; (g) comparing the grey-level values of the second data signal in one of the plurality of zones to the fixed threshold value of the zone; (h) generating binary values in response to said comparison; and (i) generating an electric representation for the original in response to the binary values.
Claim 8
Dependent Claim
17 words
The method according to claim 5 wherein the fixed threshold value is determined by prescanning the original.
Claim 9
Dependent Claim
43 words
The method according to claim 5 further comprising the step of corresponding the zone with the fixed threshold value for that zone such that each zone represents a rectangular area on the original which is divided into line segments positioned side by side.
Claim 10
Dependent Claim
76 words
The method according to claim 5 further comprising the step of comparing the grey level values of the zone to a further threshold value for the zone when a first comparison point is positioned centrally in the zone, said further threshold value corresponding to an interpolation between the fixed threshold values of several adjacent zones when a second comparison point in each adjacent zone is positioned in the rim of the zone facing said adjacent zones.
Claim 11
Dependent Claim
141 words
A scanner system comprising: (a) an optical line detector for linewise optical scanning of an original for generating a first data signal representing grey-level values of points along lines of the original; (b) means for sorting the grey-level values in zones associated with locations of the grey-level values on the original; (c) means for statistically calculating a fixed threshold value for each zone in response to a frequency of occurrence of the respective grey-level values in each zone, said calculation of the fixed threshold value starting prior to the termination of the scanning; (d) a memory in which the fixed threshold value of each zone is stored; and (e) a comparator for comparing the grey-level values in one of the zones with the fixed threshold value of the one zone, the comparator for generating a binary, electric representation of the original.
Claim 12
Dependent Claim
141 words
A scanner system comprising: (a) an optical line detector for linewise optical scanning of an original for generating a first data signal representing grey-level values of points along lines of the original; (b) means for sorting the grey-level values in zones associated with locations of the grey-level values on the original; (c) means for statistically calculating a fixed threshold value for each zone in response to a frequency of occurrence of the respective grey-level values in each zone, said calculation of the fixed threshold value starting prior to the termination of the scanning; (d) a memory in which the fixed threshold value of each zone is stored; and (e) a comparator for comparing the grey-level values in one of the zones with the fixed threshold value of the one zone, the comparator for generating a binary, electric representation of the original.
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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) | 2000-06-16 | 2000-12-16 | 2001-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-16 | 2004-12-16 | 2005-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-16 | 2008-12-16 | 2009-06-17 | $7700.00 | Window Closed / Lapsed |