Mixed screen design for multi-mode document

• US 20040051907A1
• Filed: 09/16/2002
• Published: 03/18/2004
• Est. Priority Date: 09/16/2002
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Shu, Joseph, Huang, Jincheng
• Granted Patent: US 7,212,315 B2
• Time in Patent Office: Days
• US Class Current: 358/3.06
• CPC Class Codes: H04N 1/4057 the pattern being a mixture of differently sized sub-patterns, e.g. spots having only a few different diameters multi-toning H04N1/40087

Abstract

A superpattern generator uses a first halftone pattern representing a first gray level and a second halftone pattern representing a second gray level to generate a larger pattern or “superpattern”. In a preferred implementation, the superpattern generator generates a grid of elements to be used as a template for the superpattern, calculates a distance value representing the “distance” from the first gray level to a desired gray level T_X, determines how many elements of the grid represent the first halftone pattern and how many represent the second halftone pattern based on the distance value, superimposes a dither matrix on the grid and assigns values representing the first halftone pattern or the second halftone pattern to pixels within the elements of the grid by examining threshold values in the dither matrix. This process is repeated for various values of T_X to generate a set of superpatterns representing a set of gray levels intermediate to the first gray level and the second gray level.

Claims

1. A method for generating a superpattern made up of a composition of elements, wherein the the method comprises:

receiving data that defines a first halftone pattern representing a first gray level and a second halftone pattern representing a second gray level;

constructing the composition of elements having a first quantity of elements representing the first halftone pattern and a second quantity of elements representing the second halftone pattern, wherein the first quantity and the second quantity are determined based on a distance value representing a distance from the first gray level to a desired gray level intermediate to the first gray level and the second gray level; and

transmitting or storing data representing the superpattern for use in presentation of an image.

2. The method of claim 1 wherein the composition of elements comprises a grid of pixels.

3. The method of claim 1 that arranges the elements within the composition by examining threshold values in a dither matrix.

4. The method of claim 1 wherein the distance value represents a distance from the first gray level to the desired gray level normalized with respect to a distance between the first gray level and the second gray level.

5. An apparatus comprising a memory and processing circuitry coupled to the memory wherein the processing circuitry:

receives data that defines a first halftone pattern representing a first gray level and a second halftone pattern representing a second gray level;

generates a superpattern by constructing a composition of elements having a first quantity of elements representing the first halftone pattern and a second quantity of elements representing the second halftone pattern, wherein the first quantity and the second quantity are determined based on a distance value representing a distance from the first gray level to a desired gray level intermediate to the first gray level and the second gray level; and

stores data representing the superpattern in the memory for use in presentation of an image.

6. The apparatus of claim 5 wherein the composition of elements comprises a grid of pixels.

7. The apparatus of claim 5 wherein the processing circuitry arranges the elements within the composition by examining threshold values in a dither matrix.

8. The apparatus of claim 5 wherein the distance value represents a distance from the first gray level to the desired gray level normalized with respect to a distance between the first gray level and the second gray level.

9. A medium readable by a device embodying a program of instructions for execution by the device to perform a method for generating a superpattern made up of a composition of elements, wherein the method comprises:

receiving data that defines a first halftone pattern representing a first gray level and a second halftone pattern representing a second gray level;

constructing the composition of elements having a first quantity of elements representing the first halftone pattern and a second quantity of elements representing the second halftone pattern, wherein the first quantity and the second quantity are determined based on a distance value representing a distance from the first gray level to a desired gray level intermediate to the first gray level and the second gray level; and

transmitting or storing data representing the superscreen for use in presentation of an image.

10. The medium of claim 9 wherein the composition of elements comprises a grid of pixels.

11. The medium of claim 9 wherein the method arranges the elements within the composition by examining threshold values in a dither matrix.

12. The medium of claim 9 wherein the distance value represents a distance from the first gray level to the desired gray level normalized with respect to a distance between the first gray level and the second gray level.

13. An apparatus for generating a superpattern made up of a composition of elements, wherein the apparatus comprises:

means for receiving data that defines a first halftone pattern representing a first gray level and a second halftone pattern representing a second gray level;

means for constructing the composition of elements having a first quantity of elements representing the first halftone pattern and a second quantity of elements representing the second halftone pattern, wherein the first quantity and the second quantity are determined based on a distance value representing a distance from the first gray level to a desired gray level intermediate to the first gray level and the second gray level; and

means for transmitting or storing data representing the superpattern for use in presentation of an image.

14. The apparatus of claim 13 wherein the composition of elements comprises a grid of pixels.

15. The apparatus of claim 13 that arranges the elements within the composition by examining threshold values in a dither matrix.

16. The apparatus of claim 13 wherein the distance value represents a distance from the first gray level to the desired gray level normalized with respect to a distance between the first gray level and the second gray level.