Patent Document ID: 9111131
Application ID: 13977155
Patent Status: 1

Claim One:
1. A computer-implemented method for detecting a human head in an image, comprising: receiving a depth image, the depth image comprising a foreground portion and the foreground portion comprising a first plurality of pixels; selecting a second plurality of pixels of the foreground portion of the depth image, the second plurality of pixels being equal to or less than the first plurality of pixels; for each selected pixel of the second plurality of pixels, centering a center point M(x,y) of a template with respect to the selected pixel, the template comprising the center point and a plurality of template points M(i,j), the template further comprising a circular-shaped region IR and a first annular-shaped region MR surrounding the circular shaped region, a depth of a template point M(i,j) in the circular-shaped region IR and in the first annular region MR being defined as: for ⁢ ⁢ M ⁡ ( i , j ) = ∈ IR : ⁢ { ⁢ ∑ d ≤ R c ⁢ R p 2 - d 2 / R p Num ⁡ ( IR ) · ( ∑ d ≤ R c ⁢ ( R p 2 - d 2 / R p ) + ∑ R c ≤ d ≤ R p ⁢ ( R p 2 - d 2 / R p ) ) ⁢ ⁢ and ⁢ ⁢ ⁢ for ⁢ ⁢ M ⁡ ( i , j ) ∈ MR : ⁢ { ∑ R c ≤ d ≤ R p ⁢ ( R p 2 - d 2 / R p ) Num ⁡ ( MR ) · ( ∑ d ≤ R c ⁢ ( R p 2 - d 2 / R p ) + ∑ R c ≤ d ≤ R p ⁢ ( R p 2 - d 2 / R p ) ) wherein, R p comprises a projection of a radius of the head in a view plane of the depth image, d comprises a distance between a template point M(i,j) and the center point M(x,y) of the template, R c comprises a radius of the circular-shaped region IR, Num(IR) comprises a total number of template points within the circular-shaped region IR, Num(MR) comprises a total number of template points within the first annular-shaped region MR, i and j comprise rectangular coordinate indices associated with pixels of the depth image, and x and y comprise rectangular coordinate indices associated with the template, index i corresponding to index x, and index j corresponding to index y; and determining a depth value for at least one pixel neighboring the selected pixel; determining a score H(x,y) associated with the selected pixel based on a depth value for at least one neighboring pixel in comparison to a depth value associated with a template point corresponding to the neighboring pixel; and determining a highest score of the determined scores; and selecting the pixel associated with the highest score as a center of the human head.