EP0774856A2
Expired / Lapsed
EP
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A system and method for providing a highly addressable printing system
Assignee: Xerox Corp
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Filing: 1996-11-14
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Granted: —
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Expires: 2016-11-14
Abstract
Abstract A system and process prints a high resolution image on a high addressable image output terminal by converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction. The converted image is then processed and binarized prior to being printed on a high addressable printer. The system or process utilizes a conversion circuit which includes a two-bit per pixel packing circuit, a scanline buffer circuit, a logic circuit, and a look-up table. The conversion circuit initially converts the image into an image having a lower resolution in the fast-scan direction and a higher pixel depth resolution. Thereafter, the image is further converted to an image having a lower resolution in the slow-scan direction and a higher pixel depth resolution. This conversion of a high resolution image to a lower resolution is carried without any substantial lost to the image content data.
Inventors
- 👤 Francis K. Tse
- 👤 Michael L. Davidson
- 👤 Brian C. Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:03
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40068; G; G06; G06K; G06K15/00; G06K15/02; H04N1/405; H04N1/4055; H04N1/4056; G06K2215/00; G06K2215/0002; G06K2215/0062; G06K2215/0071
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
60 words
A system for printing a high resolution image on a high addressable image output terminal, comprising: a perspective projection resolution conversion circuit; an image processing circuit, operatively connected to said perspective projection conversion circuit; a high addressable error diffusion circuit, operatively connected to said image processing circuit; and a high addressable print engine, operatively connected to said error diffusion circuit.
Claim 2
Independent Claim
87 words
A system for printing a high resolution image on a high addressable image output terminal, comprising: conversion means for converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction; processing means for image processing the converted image; converting means for converting the processed image to a renderable image having a pixel depth resolution corresponding to a printer; and print means, operatively connected to said converting means, for printing the renderable image.
Claim 3
Independent Claim
62 words
A system for printing an image, comprising: a high fast-scan resolution to low fast-scan resolution low pixel depth resolution to high pixel depth resolution conversion circuit; an image processing circuit, operatively connected to said high fast-scan resolution to low fast-scan resolution low pixel dept resolution to high pixel dept resolution conversion circuit; and a printer operatively connected to said image processing circuit.
Claim 4
Dependent Claim
110 words
The system as claimed in claim 1, 2 or 3, wherein said processing circuit comprises: input means for receiving the grey level value representing the pixel, the grey level value having a first resolution; high addressability means for converting the grey level value to a second resolution, the second resolution being higher than the first resolution; threshold means for thresholding the converted grey level value; error means for generating an error value as a result of a threshold determination by said threshold means, the error value having a resolution corresponding to the first resolution; and error diffusing means for diffusing the error value to grey level values representing adjacent pixels.
Claim 5
Independent Claim
74 words
The system as claimed in any of claims 1 to 4, wherein said high addressability means further computes a plurality of subpixel grey values B n , the subpixel grey level values B n being equal to P0+n(P1 -P0)/N, wherein n is equal to 0 to N-1, P0 is equal to the first grey level value, P1 is equal to the second grey level value, and N is equal to a high addressability characteristic.
Claim 6
Independent Claim
221 words
The system as claimed in any of claims 1 to 5, wherein the resolution conversion circuit or conversion means comprises: (A) means for converting three pixels of the image having the resolution of 1800x1800x1 to a pixel of an image having a resolution of 600x1800x2; means for summing three pixels of the image having a resolution of 600x1800x2 to generate an address; a look-up table stored in a memory; said look-up table providing a pixel of the image having the resolution of 600x600x8 from the generated address, (B) means for converting two pixels of the image having the resolution of 1200x1200x1 to a pixel of an image having a resolution of 600x1200x2; means for generating an address from two pixels of the image having the resolution of 600x1200x1; a look-up table in a memory; said look-up table providing a pixel of the image having the resolution of 600x600x8 from the generated address, or (C) means for converting nine pixels of the image having the resolution of 900x900x1 to four pixels of an image having a resolution of 600x600x4; means for generating an address from one of the pixels of the image having a resolution of 600x600x4; and a look-up table in a memory; said look-up table providing a pixel of the image having the resolution of 600x600x8 from the generated address.
Claim 7
Independent Claim
58 words
A method for printing a high resolution image on a high addressable image output terminal, comprising the steps of: (a) converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction; (b) image processing the converted image; and (c) printing the processed image.
Claim 8
Dependent Claim
98 words
The method as claimed in claim 7, wherein said step (b) comprises the substeps of: (b1) receiving the grey level value representing the pixel, the grey level value having a first resolution; (b2) converting the grey level value to a second resolution, the second resolution being higher than the first resolution; (b3) thresholding the converted grey level value; (b4) generating an error value as a result of a threshold determination in said substep (b3), the error value having a resolution corresponding to the first resolution; and (b5) diffusing the error value to grey level values representing adjacent pixels.
Claim 9
Dependent Claim
73 words
The method as claimed in claim 8, wherein said substep (b2) further comprises the substep of: (b2i) computing a plurality of subpixel grey level values B n , the subpixel grey level values B n being equal to P0+n(P1-P0)/N, wherein n is equal to 0 to N-1, P0 is equal to the first grey level value, P1 is equal to the second grey value, and N is equal to a high addressability characteristic.
Claim 10
Dependent Claim
201 words
The method as claimed in claim 7, 8 or 9, wherein said step (a) comprises (A) the substeps of: (a1) converting three pixels of the image having the resolution of 1800x1800x1 to a pixel of an image having a resolution of 600x1800x2; (a2) summing three pixels of the image having a resolution of 600x1800x2 to generate an address; and (a3) providing a pixel of the image having the resolution of 600 X 600 X 8 from the generated address, or (B) the substeps of: (a1) converting two pixels of the image having the resolution of 1200x1200x1 to a pixel of an image having a resolution of 600x1200x2; (a2) generating an address from two pixels of the image having the resolution of 600x1200x1; and (a3) providing a pixel of the image having the resolution of 600x600x8 from the generated address, or (C) the substeps of: (a1) converting nine pixels of the image having the resolution of 900x900x1 to four pixels of an image having a resolution of 600x600x4; (a2) generating an address from one of the pixels of the image having a resolution of 600x600x4; and (a3) providing a pixel of the image having the resolution of 600x600x8 from the generated address.
References Cited (Backward Citations)
EP0696132A2
Cited
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