Method and system for improved copy quality in a multifunction reprographic system

• US 7,773,254 B2
• Filed: 11/10/2005
• Issued: 08/10/2010
• Est. Priority Date: 11/10/2005
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Tse, Francis Kapo, Wu, John W., Lee, Chia-Hao, Nagarajan, Ramesh, Cassidy, John Christopher
• Primary Examiner(s): Rogers; Scott A
• Application Number:
  US11/272,182
• Publication Number:
  US 20070258101A1
• Time in Patent Office: 1,734 Days
• Field of Search: 358/1.9, 358/2.1, 358/3.01, 358/3.06, 358/3.08, 358/3.21, 358/462, 358/3.23, 382/173, 382/176, 382/205, 382/224, 382/229, 382/237, 382/254, 382/261
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/40075 Descreening, i.e. converting a halftone signal into a corresponding continuous-tone signal; Rescreening, i.e. combined descreening and halftoning

Abstract

A method and system reconstructs a contone image from a binary image by first tagging pixels to identify one of a multiplicity of image content types. The tag information and the pattern of bits surrounding the pixel to be converted to a contone value are used to reconstruct a contone image from a binary image. The pattern of bits in the neighborhood is used to generate a unique identifier. The unique identifier is used as the address for a lookup table with the contone value to be used wherein each lookup table corresponds to an image context type.

Claims

1. A system to generate a continuous tone image from tagged binary encoded image, comprising:

a binary image to contone image converter to receive binary image data and to generate contone image data;

said binary image to contone image converter including a pattern identifier generator to generate a pattern identifier value based upon the received binary image data;

said binary image to contone image converter generating contone image data based upon an image context type the received binary image data and the generated pattern identifier value.

2. The system as claimed in claim 1, wherein said binary image to contone image converter includes a plurality of look-up tables, each look-up table having a plurality of contone values stored therein, each contone value corresponding to a pattern identifier value, each look-up table corresponding to an image context type.

3. The system as claimed in claim 1, wherein said binary image to contone image converter includes a memory having a plurality of contone values stored therein, each combination of a pattern identifier value and an image context type being mapped to a stored contone value.

4. The system as claimed in claim 1, wherein said binary image to contone image converter includes a logic circuit to generate a plurality of contone values, the generated contone value corresponding to a pattern identifier value and an image context type.

5. The system as claimed in claim 1, wherein said binary image to contone image converter includes:

an image type selector to generate an image type signal corresponding to the image context type; and

a plurality of look-up tables, each look-up table having a plurality of contone values stored therein, each contone value corresponding to a pattern identifier value, each look-up table corresponding to an image context type;

said image type signal enabling a look-up table associated with the image context type corresponding to said image type signal.

6. The system as claimed in claim 1, wherein said binary image to contone image converter includes:

a plurality of look-up tables, each look-up table having a plurality of contone values stored therein, each contone value corresponding to a pattern identifier value, each look-up table corresponding to an image context type, each look-up table outputting a contone value corresponding to the pattern identifier value; and

a selector, in response to the image context type of the received binary image data, selecting one of the outputted contone values.