Foreground/Background Separation in Digital Images

• US 20100329549A1
• Filed: 09/10/2010
• Published: 12/30/2010
• Est. Priority Date: 05/03/2006
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: Tessera Technologies Ireland Limited (Adeia Inc.)
• Inventors: Steinberg, Eran, Prilutsky, Yury, Ciuc, Mihai, Zamfir, Adrian, Capata, Adrian, Bigioi, Petronel, Corcoran, Peter, Pososin, Alexei
• Granted Patent: US 8,358,841 B2
• Time in Patent Office: Days
• US Class Current: 382/164
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation
• CPC Class Codes: G06V 10/28 Quantising the image, e.g. histogram thresholding for discrimination between background and foreground patterns
• CPC Class Codes: G06V 10/56 relating to colour
• CPC Class Codes: G06V 40/162 using pixel segmentation or colour matching

Abstract

A method for providing improved foreground/background separation in a digital image of a scene is disclosed. The method comprises providing a first map comprising one or more regions provisionally defined as one of foreground or background within the digital image; and providing a subject profile corresponding to a region of interest of the digital image. The provisionally defined regions are compared with the subject profile to determine if any of the regions intersect with the profile region. The definition of one or more of the regions in the map is changed based on the comparison.

Claims

1. A method for providing foreground/background separation in a digital image of a scene comprising:

providing a first map comprising one or more regions provisionally defined as one of foreground or background within a main digital image;

analyzing one or more of said regions to determine a distribution of luminance within pixels of the region;

responsive to said luminance distribution for a region having more than one distinct luminance peak, dividing said region into more than one sub-region based on proximity of a pixel luminance to said luminance peaks; and

changing in said map a designation of said sub-regions based on said division.

2. A method as claimed in claim 1, further comprising:

providing a subject profile corresponding to a region of interest of said main digital image;

comparing at least some of said one or more provisionally defined regions with said subject profile to determine if any of said regions or sub-regions of said first map intersect with said profile region;

changing in said map a designation of one or more of said regions or sub-regions based on said comparison.

3. A method as claimed in claim 1, wherein providing said first map comprises:

analyzing at least some regions of the digital image in a color space to determine a color distribution within said regions, said color distribution having a plurality of distinct color peaks; and

segmenting said regions based on proximity of pixel color to said color peaks.

4. A method as claimed in claim 3, wherein said analyzed regions are regions provisionally defined as foreground within said first map.

5. A method as claimed in claim 3 wherein said digital image is provided in LAB space and wherein said color space comprises [a,b] values for pixels and wherein said luminance comprises L values for pixels.

6. A method for providing improved foreground/background separation in a digital image of a scene comprising of:

acquiring a main digital image;

determining at least one region of said main image including a face;

determining an orientation of said at least one face within said main image; and

defining a foreground region of said image comprising said at least one face region and a respective region below said face region in said image in accordance with said orientation.

7. An apparatus for providing foreground/background separation in a digital image of a scene, comprising a processor and one or more processor-readable media for programming the processor to control the apparatus to perform a method comprising:

acquiring a main digital image;

providing a first map comprising one or more regions provisionally defined as one of foreground or background within said main digital image;

analyzing one or more of said regions to determine a distribution of luminance within pixels of the region;

responsive to said luminance distribution for a region having more than one distinct luminance peak, dividing said region into more than one sub-region based on proximity of a pixel luminance to said luminance peaks; and

changing in said map a designation of at least one of said sub-regions based on said dividing.

8. An apparatus as claimed in claim 7, wherein the method further comprises:

providing a subject profile corresponding to a region of interest of said main digital image;

comparing at least some of said one or more provisionally defined regions with said subject profile to determine if any of said regions or sub-regions of said first map intersect with said profile region;

changing in said map a designation of one or more of said regions or sub-regions based on said comparison.

9. An apparatus as claimed in claim 7, wherein providing said first map comprises:

analyzing at least some regions of the digital image in a color space to determine a color distribution within said regions, said color distribution having a plurality of distinct color peaks; and

segmenting said regions based on proximity of pixel color to said color peaks.

10. An apparatus as claimed in claim 9, wherein said analyzed regions are regions provisionally defined as foreground within said first map.

11. An apparatus as claimed in claim 9 wherein said digital image is provided in LAB space and wherein said color space comprises [a,b] values for pixels and wherein said luminance comprises L values for pixels.

12. An apparatus for providing foreground/background separation in a digital image of a scene, comprising a processor and one or more processor-readable media for programming the processor to control the apparatus to perform a method comprising:

acquiring a main digital image;

determining at least one region of said main image including a face;

determining an orientation of said face; and

defining a foreground region of said image comprising said face and a respective region below said face in said main image in accordance with said orientation.

13. One or more computer-readable storage media having code embedded therein for programming a processor to perform a method of providing foreground/background separation in a digital image of a scene, wherein the method comprises:

providing a first map comprising one or more regions provisionally defined as one of foreground or background within a main digital image;

analyzing one or more of said regions to determine a distribution of luminance within pixels of the region;

responsive to said luminance distribution for a region having more than one distinct luminance peak, dividing said region into more than one sub-region based on proximity of a pixel luminance to said luminance peaks; and

changing in said map a designation of said sub-regions based on said division.

14. The one or more computer-readable storage media as claimed in claim 13, wherein the method further comprises:

providing a subject profile corresponding to a region of interest of said main digital image;

comparing at least some of said one or more provisionally defined regions with said subject profile to determine if any of said regions or sub-regions of said first map intersect with said profile region;

changing in said map a designation of one or more of said regions or sub-regions based on said comparison.

15. The one or more computer-readable storage media as claimed in claim 13, wherein providing said first map comprises:

analyzing at least some regions of the digital image in a color space to determine a color distribution within said regions, said color distribution having a plurality of distinct color peaks; and

segmenting said regions based on proximity of pixel color to said color peaks.

16. The one or more computer-readable storage media as claimed in claim 15, wherein said analyzed regions are regions provisionally defined as foreground within said first map.

17. The one or more computer-readable storage media as claimed in claim 15, wherein said digital image is provided in LAB space and wherein said color space comprises [a,b] values for pixels and wherein said luminance comprises L values for pixels.

18. One or more computer-readable storage media having code embedded therein for programming a processor to perform a method of providing improved foreground/background separation in a digital image of a scene, wherein the method comprises:

acquiring a main digital image;

determining at least one region of said main image including a face;

determining an orientation of said at least one face within said main image; and

defining a foreground region of said image comprising said at least one face region and a respective region below said face region in said image in accordance with said orientation.