Red-eye detection based on red region detection with eye confirmation

• US 20050053279A1
• Filed: 10/25/2004
• Published: 03/10/2005
• Est. Priority Date: 02/13/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Platt, John C., Yan, Jie, Zhang, Hong-Jiang, Chen, Xiangrong, Chen, Tong-Xian
• Granted Patent: US 7,062,086 B2
• Time in Patent Office: Days
• US Class Current: 382/165
• CPC Class Codes: G06T 2207/30216 Redeye defect
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction
• CPC Class Codes: H04N 1/624 Red-eye correction control of camera based on recognised facial parts H04N23/611

Abstract

Red-eye detection based on red region detection with eye confirmation initially identifies pixels that correspond to the color of red-eye within an image. A determination is then made as to whether these identified pixels and surrounding areas are part of an eye or not part of an eye. Those identified pixels that are determined to be part of an eye are the detected red-eye regions.

Claims

1. A system comprising:

means for receiving an image;

means for searching a set of areas of the image for candidate pixels of one or more colors, wherein the one or more colors comprise colors corresponding to red-eye;

means for combining the candidate pixels into a set of one or more pixel groups, wherein the means for combining comprises means for combining candidate pixels into the same group if the candidate pixels are adjacent one another;

means for, for each pixel group in the set of one or more pixel groups, classifying the pixel group as being part of an eye or not part of an eye;

means for checking whether flash was used in capturing the image, wherein the means for checking whether flash was used in capturing the image comprises means for checking whether a flash used flag is set in a header corresponding to the image; and

the means for searching performing the searching, the means for combining performing the combining, and the means for classifying performing the classifying only if flash was used in capturing the image.

2. A system as recited in claim 1, wherein the means for receiving comprises means for receiving the image from a camera.

3. A system as recited in claim 1, further comprising:

means for identifying areas within the image that are skin colored; and

means for using the identified areas as the set of areas.

4. A system as recited in claim 1, further comprising means for, for each pixel group in the set of one or more pixel groups, prior to the means for classifying classifying the pixel group:

identifying the geometric shape of the pixel group;

determining whether the geometric shape is similar to the shape of an eye; and

leaving the pixel group as part of the set of one or more pixel groups if the geometric shape is similar to the shape of an eye, and otherwise removing the pixel group from the set.

5. A system as recited in claim 4, wherein the shape is similar to the shape of an eye if the geometric shape is more circular than rectangular and if an aspect ratio of the geometric shape differs from the aspect ratio of a circle by not greater than a particular amount.

6. A system as recited in claim 1, wherein the means for classifying comprises:

means for applying a window to the image and comparing pixels within the window to an eye template;

means for altering the scale of the image; and

means for repeating the applying and comparing based on the scale-altered image.

7. A system as recited in claim 6, wherein the means for repeating comprises means for repeating the applying and comparing based on the scale-altered image without altering the size of the eye template.

8. A system as recited in claim 1, further comprising means for removing, based on a set of rules, groups from the set of one or more pixel groups.