Image processing method and apparatus for white eye correction

• US 20050238230A1
• Filed: 04/26/2005
• Published: 10/27/2005
• Est. Priority Date: 04/26/2004
• Status: Active Grant

• Current Assignee: Noritsu Koki Co., Ltd.
• Original Assignee: Noritsu Koki Co., Ltd.
• Inventors: Yoshida, Ikuko
• Granted Patent: US 7,298,380 B2
• Time in Patent Office: Days
• US Class Current: 382/167
• CPC Class Codes: G06T 2207/30216 Redeye defect
• 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 1/62 Retouching, i.e. modification of isolated colours only or in isolated picture areas only
• CPC Class Codes: H04N 1/624 Red-eye correction control of camera based on recognised facial parts H04N23/611
• CPC Class Codes: H04N 1/628 Memory colours, e.g. skin or sky

Abstract

A technique for correcting white eye in image data is disclosed. In this technique, a white eye candidate pixel is detected from an eye extracted from the image data based on a predetermined detection condition. The white eye candidate pixel as a white eye pixel based on a predetermined determination condition. Then, white eye correction is effected on the determined white eye pixel by changing its luminance.

Claims

1. A method for correcting white eye in image data, comprising the steps of:

detecting a white eye candidate pixel from an eye extracted from the image data based on a predetermined detection condition;

determining said white eye candidate pixel as a white eye pixel based on a predetermined determination condition; and

effecting white eye correction of the determined white eye pixel by changing its luminance.

2. The method according to claim 1, further comprising the step of detecting an iris from the image data, and at said white eye pixel determining step, wherein said white eye candidate pixel is determined as the white eye pixel if said white eye candidate pixel has been detected from an area adjacent said iris.

3. The method according to claim 1, wherein said white eye correcting step is effected by changing a chroma of the white eye pixel first prior to the change of its luminance.

4. The method according to claim 3, wherein the white eye correcting step is effected by changing a hue of the white eye pixel.

5. The method according to claim 1, wherein the white eye correcting step effects the white eye correction by a ratio determined based on a difference between a predetermined pixel value of a target pixel and a pixel value of each white eye pixel.

6. The method according to claim 1, wherein said predetermined detection condition employed at said step of detecting a white eye candidate pixel is predetermined based on a luminance distribution of the image data.

7. A computer-readable medium comprising computer-executable instructions for correcting white eye in image data, said instructions comprising the steps of:

detecting a white eye candidate pixel from an eye extracted from the image data based on a predetermined detection condition;

determining said white eye candidate pixel as a white eye pixel based on a predetermined determination condition; and

effecting white eye correction of the determined white eye pixel by changing its luminance.

8. An image processing apparatus for correcting white eye in image data, the apparatus comprising:

a white eye candidate pixel detecting section for detecting a white eye candidate pixel from an eye extracted from the image data based on a predetermined detection condition

a white eye pixel determining section for determining said white eye candidate pixel as a white eye pixel based on a predetermined determination condition; and

a white eye correcting section for effecting white eye correction of the determined white eye pixel by changing its luminance.

9. The apparatus according to claim 8, further comprising:

a white eye determination condition calculating section for detecting an iris from the image data;

wherein said white eye pixel determining section determines said white eye candidate pixel as the white eye pixel if said white eye candidate pixel has been detected from an area adjacent said iris.

10. The apparatus according to claim 8, wherein said white eye correcting section effects the white eye correction by changing a chroma of the white eye pixel first prior to the change of its luminance.

11. The apparatus according to claim 10, wherein said white eye correcting section effects the white eye correction by changing a hue of the white eye pixel.

12. The apparatus according to claim 8, wherein said white eye correcting section effects the white eye correction by a ratio determined based on a difference between a predetermined pixel value of a target pixel and a pixel value of each white eye pixel.

13. The apparatus according to claim 8, wherein said white eye candidate pixel detecting section detects a white eye candidate pixel based on a luminance distribution of the image data.