Image segmentation using bayes risk estimation of scene foreground and background

An apparatus for segmenting an object from within an image, comprising:

• (a) at least one processor configured for processing of a received image;
• and
• (b) memory storing instructions;
• (c) said instructions when executed by the processor performing steps comprising:
• (i) receiving an image, comprising pixels, and at least a selection point for an object being selected in said image to which image segmentation is to be performed, within an electronic device configured for performing image processing;
• (ii) receiving additional image information comprising depth information, or contrast mapping, or texture mapping, or any combination of this information, upon which to assess risk and make segmentation decisions;
• (iii) quantizing the image to obtain information utilized in selecting area in pre-determined areas, comprising areas of definite foreground, definite background, initial foreground, initial background;
• (iv) estimating areas of the image covered by the definite foreground, by the definite foreground, the definite background, the initial foreground, and the initial background;
• (v) assigning sets of risk values to each of said definite foreground, the definite background, the initial foreground, and the initial background;
• (vi) wherein each of said risk values comprises a cost value Cfb if segmentation decides on foreground for an element that should be background, and a cost value Cbf if segmentation decides on background for an element that should be in the foreground;
• (vii) wherein for said initial foreground, a cost value Cbf is assigned which is higher than cost value Cfb, while for said initial background a cost value Cfb is assigned which is higher than cost value Cbf;
• (viii) wherein for said definite foreground, a cost value Cbf is assigned which is significantly larger than cost value Cfb, while for said definite background a cost value Cfb is assigned which is significantly higher than cost value Cbf with a difference between cost values assigned to the definite foreground and definite background being significantly larger than assigned to the initial foreground and initial background;
• and
• (ix) making segmentation decisions for the pixels in the image based on information from that image, and modifying those segmentation decisions based on the cost values of the area in which the pixels are found.

A method of segmenting an object from within an image, comprising:

• (a) receiving an image, comprising pixels, and at least a selection point for an object being selected in said image to which image segmentation is to be performed, within an electronic device configured for performing image processing;
• (b) quantizing the image to obtain information utilized in selecting area in pre-determined areas, comprising areas of definite foreground, definite background, initial foreground, initial background;
• (c) estimating areas of the image covered by the definite foreground, the definite background, the initial foreground, and the initial background;
• (d) assigning sets of risk values to each of said definite foreground, the definite background, the initial foreground, and the initial background;
• (e) wherein each of said risk values comprises a cost value Cfb if segmentation decides on foreground for an element that should be background, and a cost value Cbf if segmentation decides on background for an element that should be in the foreground;
• (f) wherein for said initial foreground, a cost value Cbf is assigned which is higher than cost value Cfb, while for said initial background a cost value Cfb is assigned which is higher than cost value Cbf;
• (g) wherein for said definite foreground, a cost value Cbf is assigned which is significantly larger than cost value Cfb, while for said definite background a cost value Cfb is assigned which is significantly higher than cost value Cbf with a difference between cost values assigned to the definite foreground and definite background being significantly larger than assigned to the initial foreground and initial background;
• and
• (h) making segmentation decisions for the pixels in the image based on information from that image, and modifying those segmentation decisions based on the cost values of the area in which the pixels are found.