Patent EP1067765A2 successfully refreshed from Google Patents.
EP1067765A2
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EP
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Compact-dot reproduction of scanned halftone screens
Assignee: Xerox Corp
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Filing: 2000-06-30
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Granted: —
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Expires: 2020-06-30
Abstract
Abstract A method of reproducing a document including halftoned regions therein scans the document to generate scanned image data comprising a digitized representation of said document. The scanned image data that corresponds to the halftoned regions is then rendered using a compact rendering process that includes positioning an observation window about a target pixel and a neighboring pixel; selecting a fill-order based upon a result of the analyzing step; and generating a high addressability pixel as a function of the selected fill-order.
Inventors
- 👤 Robert P. Loce
- 👤 Michael Branciforte
- 👤 Yequing Zhang
- 👤 Leon C. Williams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:23
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40075; H04N1/405; H04N1/4055; H04N1/4056
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
105 words
A method of processing a document including a halftoned region therein,
comprising: scanning said document to generate scanned image data, said scanned image
data comprising a digitized representation of said document, and applying a compact rendering process to a target pixel within said image data
that corresponds to a pixel within said halftoned region, said compact
rendering process including: positioning an observation window about said target pixel, said observation
window comprising a pixel neighboring the target pixel; analyzing said neighboring pixel; selecting a fill-order based upon a result of said analyzing step; and generating a high addressability pixel as a function of said selected fill-order.
Claim 2
Dependent Claim
26 words
The method of claim 1, wherein said step of analyzing said target pixel further
comprises determining a difference between said target pixel and said neighboring
pixel.
Claim 3
Dependent Claim
30 words
The method of claim 2, wherein said step of selecting a fill-order identifies a
rendering pattern that fills high addressability pixel events from a darker pixel
towards a lighter pixel.
Claim 4
Dependent Claim
35 words
The method of claim 1, further comprising applying said compact rendering
process to a second target pixel, wherein said second target pixel is selected from
said image data that corresponds to a text/line art region.
Claim 5
Dependent Claim
34 words
The method of claim 1, wherein said step of generating a high addressability
pixel is accomplished as a function of said selected fill-order and the value of said
target pixel and marking process characteristics.
Claim 6
Dependent Claim
20 words
The method of claim 1, further comprising diffusing an error resulting from said
step of generating a high addressability pixel.
Claim 7
Dependent Claim
33 words
The method of claim 6, wherein said step of diffusing an error comprises: determining a quantization error and distributing the quantization error to a number of pixels within said scanned
video image data.
Claim 8
Dependent Claim
60 words
The method of claim 7, wherein said step of dertemining a quantization error
comprises: comparing the gray level of the target pixel with the gray level of the high
addressability pixel; and generating a rendering error signal that is measure of a difference between the
output density of the target pixel and the output density of the high
addressability pixel.
Claim 9
Dependent Claim
32 words
The method of claim 7, wherein said step of distributing the quantization error
distributes a weighted portion of the quantization error to a preselected number
pixels within said scanned video image data.
Claim 10
Independent Claim
97 words
A system for reproducing a document, comprising: a scanner for generating a digitized representation of said document, said
digitized representation comprising a plurality of multi-bit pixels; a segmentation circuit coupled to receive said digitized representation from said
scanner, said segmentation circuit classifying a pixel into at least one of a
plurality of image classes; and an image processing circuit, coupled to receive said digitized representation
from said scanner and responsive to said segmentation circuit, said image
processing circuit including a compact rendering module for rendering a
target pixel classified as a halftone as a high addressability pixel.
References Cited (Backward Citations)
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