Edge enhancement which reduces the visibility of false contours

• US 6,259,822 B1
• Filed: 10/30/1998
• Issued: 07/10/2001
• Est. Priority Date: 10/30/1998
• Status: Expired due to Term

• Current Assignee: Monument Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Eastman Kodak Company
• Inventors: Adams, James E. Jr., Hamilton, John F. Jr.
• Primary Examiner(s): Lee, Thomas D.
• Assistant Examiner(s): BRINICH, STEPHEN M
• Application Number:
  US09/183,147
• Time in Patent Office: 984 Days
• Field of Search: 382/199, 382/266-269, 382/260-265
• US Class Current: 382/266
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening

Abstract

A method of edge enhancing a digital image having pixels which reduces the visibility of false edge contours and includes acquiring a digital image; computing an edge boost record having positive and negative boost values for different portions of the edge regions in a digital image; modifying the edge boost record by applying an adaptive blur kernel to the pixels of such edge boost record; and applying the modified edge boost record to the digital image to provide an edge enhanced digital image which reduces the visibility of false edge contours.

Claims

1. A method of edge enhancing a digital image having pixels which reduces the visibility of false edge contours, comprising the steps of:

a) acquiring a digital image;

b) computing an edge boost record having positive and negative boost values for different portions of the edge regions in a digital image;

c) modifying the edge boost record by applying an adaptive blur kernel to the pixels of said edge boost record by;

(i) providing the blur kernel in response to the boost values of a predetermined number of pixels near the pixel of interest; and

(ii) using the geometric pattern of positive and negative boost values in constructing the blur kernel so that only non-negative boost values are used to modify a non-negative boost value, and only non-positive boost values are used to modify a non-negative boost value; and

d) applying the modified edge boost record to the digital image to provide an edge enhanced digital image which reduces the visibility of false edge contours.

2. The method of claim 1 wherein the adaptive blur kernel is a function of the edge boost record.

3. The method of claim 1 wherein the adaptive blur kernel is a 3×

3 kernel.

4. The method of claim 1 wherein the modified edge boost record is applied to the digital image by summing at each pixel.

5. A computer program product for edge enhancement of a digital image having pixels, comprising a computer readable storage medium having a computer program stored thereon for performing the steps of:

a) acquiring a digital image;

b) computing an edge boost record having positive and negative boost values for different portions of the edge regions in a digital image;

c) modifying the edge boost record by applying an adaptive blur kernel to the pixels of said edge boost record by;

(i) providing the blur kernel in response to the boost values of a predetermined number of pixels near the pixel of interest; and

(ii) using the geometric pattern of positive and negative boost values in constructing the blur kernel so that only non-negative boost values are used to modify a non-negative boost value, and only non-positive boost values are used to modify a non-negative boost value; and

d) applying the modified edge boost record to the digital image to provide an edge enhanced digital image.