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US6181829B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Method and system for classifying and processing of pixels of image data

Assignee: Xerox Corp
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Filing: 1998-01-21
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Granted: 2001-01-30
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Expires: 2018-01-21
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Abstract

Abstract A system and method classify a pixel of image data as one of a plurality of image types. A first image characteristic value for the pixel, a second image characteristic value for the pixel ,a third image characteristic value for the pixel, and a fourth image characteristic for the pixel is determined. Some of these determinations may be resolution dependent. The values from these determination are utilized in assigning an image type classification to the pixel. Moreover, if at least one of the image characteristic values is greater than a predetermined threshold value the pixel is classified as a halftone peak value. The system includes a plurality of microclassifiers for determining a distinct image characteristic value of the pixel; a plurality of macroreduction circuits connected to the plurality of microclassifiers for performing further higher level operations upon the distinct image characteristic values of the pixel to produce reduced values; and a classification circuit to classify the pixel as an image type based on the reduced values from the macroreduction circuits. The system also includes a circuit to detect flat peaks without detecting multiple peaks and a rectangular blur filtering system.

Inventors

  • 👤 Raymond J. Clark
  • 👤 Leon C. Williams
  • 👤 Stuart A. Schweid
  • 👤 Jeng-Nan Shiau

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 16:28
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40062

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 127 words
A method for determining a halftone frequency of a pixel of image data in a window of pixels, comprising the steps of: (a) determining if the pixel represents a peak and generating a peak value therefrom; (b) fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value; (c) fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value; (d) determining a peak count from a previous first peak count value generated from a previous execution of said step (b) and the second peak count value of said step (c); and (e) calculating a halftone frequency based on the peak count determined in said step (d).
Claim 2
Independent Claim 127 words
A method for determining a halftone frequency of a pixel of image data in a window of pixels, comprising the steps of: (a) determining if the pixel represents a peak and generating a peak value therefrom; (b) fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value; (c) fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value; (d) determining a peak count from a previous first peak count value generated from a previous execution of said step (b) and the second peak count value of said step (c); and (e) calculating a halftone frequency based on the peak count determined in said step (d).
Claim 3
Independent Claim 126 words
A system for determining a halftone frequency of a pixel of image data in a window of pixels, comprising: peak detection means for determining if the pixel represents a peak and generating a peak value therefrom; first filter means for fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value therefrom; second filter means for fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value therefrom; peak count means for determining an actual peak count from a previous first peak count value and said second peak count value; and halftone frequency means for calculating a halftone frequency based on the actual peak count value.
Claim 4
Independent Claim 126 words
A system for determining a halftone frequency of a pixel of image data in a window of pixels, comprising: peak detection means for determining if the pixel represents a peak and generating a peak value therefrom; first filter means for fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value therefrom; second filter means for fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value therefrom; peak count means for determining an actual peak count from a previous first peak count value and said second peak count value; and halftone frequency means for calculating a halftone frequency based on the actual peak count value.
Claim 5
Dependent Claim 59 words
The system as claimed in claim 2 , wherein said first filter means comprises: a programmable delay line which receives the peak value from said peak detection means to produce a delayed peak value; and a peak counter to generate said first peak count value from the peak value, delayed peak value, and a previous first peak count value.
Claim 6
Dependent Claim 59 words
The system as claimed in claim 2 , wherein said second filter means comprises: a programmable delay line which receives the peak value from said peak detection means to produce a delayed peak value; and a peak counter to generate said second peak count value from the peak value, delayed peak value, and a previous second peak count value.
Claim 7
Dependent Claim 62 words
The system as claimed in claim 3 , wherein said first filter means comprises: a second programmable delay line which receives the peak value from said peak detection means to produce a second delayed peak value; and a peak counter to generate said second peak count value from the peak value, second delayed peak value, and a previous second peak count value.
Claim 8
Dependent Claim 16 words
The system as claimed in claim 2 , wherein said peak count means includes an adder.
Claim 9
Dependent Claim 166 words
A printing system for rendering a pixel of image data, comprising: peak detection means for determining if the pixel within a window of pixels represents a peak and generating a peak value therefrom; first filter means for fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value therefrom; second filter means for fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value therefrom; peak count means for determining an actual peak count from a previous first peak count value and said second peak count value; halftone frequency means for calculating a halftone frequency based on the actual peak count value; classification means for classifying the pixel as a particular image type based on the calculated halftone frequency; processing means for image processing the pixel based the image type classification of the pixel; and print means for rendering the processed pixel on a recording medium.
Claim 10
Dependent Claim 166 words
A printing system for rendering a pixel of image data, comprising: peak detection means for determining if the pixel within a window of pixels represents a peak and generating a peak value therefrom; first filter means for fastscan blur filtering the peak value at a slowscan lead edge of the window to generate a first peak count value therefrom; second filter means for fastscan blur filtering the peak value at a slowscan trail edge of the window to generate a second peak count value therefrom; peak count means for determining an actual peak count from a previous first peak count value and said second peak count value; halftone frequency means for calculating a halftone frequency based on the actual peak count value; classification means for classifying the pixel as a particular image type based on the calculated halftone frequency; processing means for image processing the pixel based the image type classification of the pixel; and print means for rendering the processed pixel on a recording medium.
Claim 11
Dependent Claim 59 words
The system as claimed in claim 7 , wherein said first filter means comprises: a programmable delay line which receives the peak value from said peak detection means to produce a delayed peak value; and a peak counter to generate said first peak count value from the peak value, delayed peak value, and a previous first peak count value.
Claim 12
Dependent Claim 59 words
The system as claimed in claim 7 , wherein said second filter means comprises: a programmable delay line which receives the peak value from said peak detection means to produce a delayed peak value; and a peak counter to generate said second peak count value from the peak value, delayed peak value, and a previous second peak count value.
Claim 13
Dependent Claim 62 words
The system as claimed in claim 8 , wherein said first filter means comprises: a second programmable delay line which receives the peak value from said peak detection means to produce a second delayed peak value; and a peak counter to generate said second peak count value from the peak value, second delayed peak value, and a previous second peak count value.
Claim 14
Dependent Claim 16 words
The system as claimed in claim 7 , wherein said peak count means includes an adder.

References Cited (Backward Citations)

US4288821A Cited
US4447830A Cited
US5343309A Cited
US5485289A Cited
US5550569A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-01-30 2004-07-31 2005-01-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-01-30 2008-07-31 2009-01-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-01-30 2012-07-31 2013-01-30 $7700.00 Window Closed / Lapsed

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