Patent Document ID: 7657113
Application ID: 11313421
Patent Flag: 1

Claim One:
1. A method for denoising a digital image or a digital video containing at least one video frame, comprising producing a filtered output for a current pixel of said digital image or video frame using a past filtered pixel as an input, said filtered output being a weighted sum of said past filtered pixel and a set of neighboring pixels which comprises one or more future pixels surrounding said current pixel, said weighted sum being calculated by applying a spatial varying filter coefficient, wherein said weighted sum is calculated according to Equation (5); y ⁡ ( i , j ) = ∑ ( k , l ) ∈ N ( k , l ) < ( 0 , 0 ) , ⁢ a ⁡ ( i + k , j + l ) · y ⁡ ( i + k , j + l ) + ∑ ( k , l ) ∈ N ( k , l ) ≥ ( 0 , 0 ) , ⁢ a ⁡ ( i + k , j + l ) · x ⁡ ( i + k , j + l ) ( 5 ) w ⁡ ( i + k , j + l ) = { f ⁡ (  x ⁡ ( i , j ) - y ⁡ ( i + k , j + l )  ) , ( k , l ) < ( 0 , 0 ) f ⁡ (  x ⁡ ( i , j ) - x ⁡ ( i + k , j + l )  ) , ( k , l ) ≥ ( 0 , 0 ) ( 6 ) a ⁡ ( i + k , j + l ) = w ⁡ ( i + k , j + l ) ∑ ( k , l ) ∈ N ⁢ w ⁡ ( i + k , j + l ) ( 7 ) where, y(i,j) is weighted sum of the input; x(i,j) is (i,j)th pixel of said digital image or video frame; a(i+k, j+l) is said spatial varying filter coefficient determined by a function ƒ of absolute pixel difference defined by Equation (6) and normalized by Equation (7); and N is said set of neighboring pixels.