Patent Document ID: 9582862
Application ID: 15022872
Patent Flag: 1

Claim One:
1. A direction-adaptive image deblurring method, comprising steps of: (1) defining a minimum cost function for deblurring an image by direction-adaptive total variation regularization as follows: min u ⁢ 〈 1 , Hu - f ⁢ ⁢ log ⁡ ( Hu ) 〉 + λ ⁢  a → · ∇ u  1 , where u represents an image to be restored, H is a point spread function, ƒ is a degraded image, λ is a regularization parameter and λ>0, ∥{right arrow over (a)}·∇u∥ 1 represents an l 1 -Norm of a vector {right arrow over (a)}·∇u, {right arrow over (a)} is a direction vector and {right arrow over (a)}=(a 1 , a 2 ), ∇u is a gradient operator and ∇ u = ( ∇ x ⁢ u ∇ y ⁢ u ) , · is a vector dot product operator, a → · ∇ u = ( a 1 ⁢ ∇ x ⁢ u a 2 ⁢ ∇ y ⁢ u ) , is an inner product operator, log is a logarithmic function, and min u ⁢ 〈 1 , Hu - f ⁢ ⁢ log ⁡ ( Hu ) 〉 represents calculating a minimum of an energy function 1, Hu−ƒ log(Hu) and outputting a corresponding u; (2) converting the unconstrained minimization problem in step (1) to a constrained problem by auxiliary variables d 1 , d 2 , and d 3 as follows: { min u , d 1 , d 2 , d 3 ⁢ 〈 1 , d 1 - f ⁢ ⁢ log ⁡ ( d 1 ) 〉 + λ || a 1 ⁢ d 2 ⁢ || 1 ⁢ + λ || a 2 ⁢ d 3 ⁢ || 1 s. t. ⁢ d 1 = Hu , d 2 = ∇ x ⁢ u , d 3 = ∇ y ⁢ u ⁢ , where d 1 =Hu, d 2 =∇ x u and d 3 =∇ y u; (3) obtaining a new minimum cost function from the constrained problem in step (2) by introducing penalty terms as follows: min u , d 1 , d 2 , d 3 ⁢ 〈 1 , d 1 - f ⁢ ⁢ log ⁡ ( d 1 ) 〉 + λ || a 1 ⁢ d 2 ⁢ || 1 ⁢ + λ || + ⁢ α 2 ⁢ a 2 ⁢ d 3 ⁢ || 1 || d 1 - Hu ⁢ || 2 2 ⁢ + β 2 || d 2 - ∇ x ⁢ u ⁢ || 2 2 ⁢ + γ 2 || d 3 - ∇ y ⁢ u ⁢ || 2 2 , where α, β and γ are penalty parameters greater than zero; and (4) converting the minimization problem in step (3) to an alternating minimization problem about u, d 1 , d 2 and d 3 , where a minimum of a variable is calculated as other variables are determined, and obtaining a deblurred image by solving the alternating minimization problem by an alternative and iterative minimization process.