SYSTEMS AND METHODS FOR LINE WIDTH CONTROL AND PIXEL RETAGGING

• US 20100128314A1
• Filed: 11/24/2008
• Published: 05/27/2010
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Loce, Robert P., Xu, Beilei, Schweid, Stuart A.
• Granted Patent: US 8,467,089 B2
• Time in Patent Office: Days
• US Class Current: 358/3.60
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 2207/30176 Document
• CPC Class Codes: G06T 5/003 Deblurring; Sharpening vibration or motion blur correction for cameras comprising an electronic image sensor H04N23/682
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 1/4092 Edge or detail enhancement

Abstract

A system and method for processing a digital image for rendering are provided. The method includes performing one or more Line Width Control (LWC) operations on digital image data including pixels having pixel values representing gray levels and tag states providing information for specialized rendering techniques thereby changing one or more pixel values resulting in one or more inaccurate pixel tag states, identifying and reassigning one or more inaccurate pixel tag states for improving the rendering of the resultant digital image. An apparatus, such as an image processing system, capable of performing line width control and tag reassignment is also provided.

Claims

1. A method for processing a digital image for rendering, the method:

comprising;

receiving digital image data including pixels having pixel values representing gray levels, at least some of the pixels having tag states;

performing one or more Line Width Control (LWC) operations on the digital image data changing one or more pixel values resulting in one or more inaccurate pixel tag states; and

revising one or more inaccurate pixel tag states for improving the rendering of the digital image.

2. The method of claim 1 further comprising rendering a portion of the image using halftoning and rendering a portion of the image having anti-aliased pixel tag states using anti-aliased rendering.

3. The method of claim 1 wherein the LWC operation includes a line modification moving at least one image edge one of an outward direction and an inward direction.

4. The method of claim 1 wherein the revising includes reassigning pixel tag states for pixels having pixel values changed by the one or more LWC operations.

5. The method of claim 1 wherein the revising includes reassigning pixel tag states for pixels having neighbor pixel (NP) pixel values changed by the one or more LWC operations.

6. The method of claim 5 wherein the revising includes reassigning pixel tag states for pixels having nearest neighbor pixel (NNP) pixel values changed by the one or more LWC operations.

7. The method of claim 1 wherein the revising includes reassigning pixel tag states to either foreground tag state values or null states for anti-aliased edge pixels having pixel values changed to foreground pixel values in the one or more LWC operations.

8. The method of claim 1 wherein the revising includes reassigning pixel tag states to either background tag state values or null states for anti-aliased edge pixels having pixel values changed to background pixel values in the one or more LWC operations.

9. The method of claim 1 wherein the revising includes reassigning pixel tag states to anti-aliased pixel tag states when pixels neighboring anti-aliased pixels and having foreground or background pixel values that are changed to intermediate pixel values in the one or more LWC operations.

10. The method of claim 1 wherein the revising includes reassigning pixel tag states to provide accurate distance to edge information for pixel tag states having inaccurate distance to edge information resulting from changes to an image edge made in the one or more LWC operations.

11. A method of digital image Line Width Control comprising:

receiving digital image data including pixels having pixel values representing gray levels, at least some of the pixels having tag states;

performing a Line Width Control (LWC) operation on the digital image data changing one or more pixel values resulting in one or more inaccurate pixel tag states;

performing pixel evaluation and tag state reassignment reassigning tag states for one or more pixels having inaccurate pixel tag states; and

outputting the digital image data having accurate pixel tag states for the rendering of the digital image.

12. An apparatus for processing images, comprising;

an image processing system performing a Line Width Control (LWC) operation on digital image data including pixels having pixel values representing gray levels, at least some of the pixels having tag states, the LWC operation changing one or more pixel values resulting in one or more inaccurate pixel tag states, the image processing system performing pixel evaluation and tag state reassignment identifying one or more pixels having inaccurate tag states and reassigning the tag states for the one or more pixels having inaccurate pixel tag states.

13. The apparatus of claim 12 further comprising the image processing system rendering a portion of the image in a first rendering operation utilizing pixel tag state information and rendering a portion of the image in a second rendering operation not utilizing pixel tag state information.

14. The apparatus of claim 12 further comprising the image processing system rendering a portion of the image using halftoning and rendering a portion of the image having anti-aliased pixel tag states using anti-aliased rendering.

15. The apparatus of claim 12 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states for pixels having neighbor pixel (NP) pixel values changed by the LWC operation.

16. The apparatus of claim 15 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states for pixels having nearest neighbor pixel (NNP) pixel values changed by the one or more LWC operations.

17. The apparatus of claim 12 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states to either foreground tag state values or null states for anti-aliased edge pixels having pixel values changed to foreground pixel values in the LWC operation and reassigns pixel tag states to either background tag state values or null states for anti-aliased edge pixels having pixel values changed to background pixel values in the LWC operation.

18. The apparatus of claim 12 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states to “

1-in”

or from “

1-in”

, or reassigns pixel tag states to “

1-out”

or from “

1-out”

.

19. The apparatus of claim 12 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states to anti-aliased pixel tag states when pixels neighboring anti-aliased pixels and having foreground or background pixel values that are changed to intermediate pixel values in the LWC operation.

20. The apparatus of claim 12 wherein the image processing system performing pixel evaluation and tag state reassignment reassigns pixel tag states to provide accurate distance to edge information for pixel tag states having inaccurate distance to edge information resulting from changes to an image edge made in the LWC operation.