Optimized Performance and Performance for Red-Eye Filter Method and Apparatus

• US 20080002060A1
• Filed: 06/27/2007
• Published: 01/03/2008
• Est. Priority Date: 10/09/1997
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: FotoNation Vision Limited (Adeia Inc.)
• Inventors: DeLuca, Michael, Steinberg, Eran, Prilutsky, Yury, Capata, Adrian, Nanu, Florin, Drimbarean, Alexandru, Bigioi, Petronel, Corcoran, Peter, Pososin, Alexei
• Granted Patent: US 7,474,341 B2
• Time in Patent Office: Days
• US Class Current: 348/576
• CPC Class Codes: G06T 2207/30216 Redeye defect
• CPC Class Codes: G06T 5/005 Retouching; Inpainting; Scratch removal detecting, correction, reducing or removing defects, e.g. non-responsive pixels of solid state image sensors H04N25/68, scratch removal for cinematographic films scanned by electronic image sensor H04N5/253
• CPC Class Codes: G06T 5/77 Retouching; Inpainting; Scratch removal
• 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 23/74 by influencing the scene brightness using illuminating means

Abstract

A digital camera has an integral flash and stores and displays a digital image. Under certain conditions, a flash photograph taken with the camera may result in a red-eye phenomenon due to a reflection within an eye of a subject of the photograph. A digital apparatus has a red-eye filter which analyzes the stored image for the red-eye phenomenon and modifies the stored image to eliminate the red-eye phenomenon by changing the red area to black. The modification of the image is enabled when a photograph is taken under conditions indicative of the red-eye phenomenon. The modification is subject to anti-falsing analysis which further examines the area around the red-eye area for indicia of the eye of the subject. The detection and correction can be optimized for performance and quality by operating on subsample versions of the image when appropriate.

Claims

1. A portable digital camera having no photographic film, comprising:

(a) an integral flash for providing illumination during image acquisition;

(b) a digital image capturing apparatus for acquiring an image; and

(c) an image store for holding;

(i) a temporary copy of an unprocessed image known as a pre-capture image;

(ii) a permanent copy of a digitally processed, captured image, and

(iii) a subsample representation of selected regions of the pre-capture image; and

(d) a red-eye filter for modifying an area within said at least one of the images indicative of a red-eye phenomenon based on an analysis of the subsample representation.

2. The camera of claim 1, wherein said at least one of the images comprises the digitally processed, captured image.

3. The camera of claim 2, wherein said subsample representation of selected regions of said image is determined in hardware.

4. The camera of claim 2, wherein said analysis is performed in part on the full resolution image and in part on a subsample resolution of said image.

5. The camera of claim 2, further comprising a module for changing the degree of said subsampling.

6. The camera of claim 5, wherein said changing the degree of said subsampling is determined empirically.

7. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on a size of said image.

8. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on a region size.

9. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on a complexity of calculation for said red eye filter.

10. The camera of claim 5, wherein said subsample representation is determined using a spline interpolation.

11. The camera of claim 5, wherein said subsample representation is determined using bi-cubic interpolation.

12. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on data obtained from the camera relating to the settings of the camera at the time of image acquisition.

13. The camera of claim 12, wherein the data obtained from the camera includes an aperture setting or focus of the camera, or both.

14. The camera of claim 12, wherein the data obtained from the camera includes the distance of the subject from the camera.

15. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on data obtained from the camera relating to image processing analysis of said precapture images.

16. The camera of claim 15, wherein said image processing analysis is based on histogram data obtained from said pre-capture image.

17. The camera of claim 15, wherein said image processing analysis is based on color correlogram data obtained from said pre-capture image.

18. The camera of claim 15, wherein said image processing analysis is based on global luminance or white balance image data, or both, obtained from said pre-capture image.

19. The camera of claim 15, wherein said image processing analysis is based on face detection analysis of said pre-capture image.

20. The camera of claim 15, wherein said image processing analysis is based on determining pixel regions with a color characteristic indicative of redeye.

21. The camera of claim 15, wherein said image processing analysis is performed in hardware.

22. The camera of claim 5, wherein said changing the degree of said subsampling is determined based on image metadata information.

23. The camera of claim 2, wherein said modifying the area is performed including the full resolution of said image.

24. The camera of claim 2, wherein said red-eye filter comprises a plurality of sub filters.

25. The camera of claim 1, further comprising:

(d) a pixel locator for locating pixels having a color indicative of the red-eye phenomenon;

(e) a shape analyzer for determining if a grouping of at least a portion of the pixels located by the pixel locator comprise a shape indicative of the red-eye phenomenon; and

(f) a pixel modifier for modifying the color of the pixels within the grouping.

26. The camera of claim 25, further comprising a falsing analyzer for further processing the image in a vicinity of the grouping for details indicative of an eye, and for enabling the pixel modifier in response thereto.

27. The camera of claim 25, further comprising an exposure analyzer for determining if the image was acquired in a condition indicative of the red-eye phenomenon.