Patent ID: 8379943

Claim:
A high-performance fingerprint image-processing method comprising the following steps: determining the fingerprint direction being to apply numerical equations within a processor to further read and determine the fingerprint direction in part of characteristic ridges from a collected Gray-Scale image of an original fingerprint; linear filtering of composite filtering being to apply definition equations of linear mask filter within the processor and to rotate a linear spatial filter within the processor based on the determined fingerprint direction in part to perform a filtering operation at each point on the collected fingerprint image; rhombus filtering of composite filtering being to apply definition equations of rhombus mask filter within the processor and to rotate a rhombus spatial filter within the processor based on the fingerprint direction of the fingerprint image, which has been linear filtered to perform a filtering operation at each point on the collected fingerprint image; and binarizing being to perform a binarizing operation for the fingerprint image that has been rhombus filtered by the processor in order to demonstrate the effect of image enhancement; wherein the linear spatial filter and the rhombus spatial filter within the processor apply a filtering mask with a coefficient 9×3 to perform the mask filtering operation; wherein the definition equations of linear mask filtering applied in the linear filtering of composite filtering step are: W = [ 0 0 0 0 0 0 0 0 0 1 1 0 1 0 1 0 1 1 0 0 0 0 0 0 0 0 0 ] K = ∑ u = 0 2 ⁢ n + 1 ⁢ ∑ v = 0 2 ⁢ ⁢ m + 1 ⁢ W ⁡ ( u , v ) ⁢ i ′ = i + ( ( u - ( n + 1 ) ) · cos ⁢ ⁢ θ ⁡ ( i , j ) + ( v - ( m + 1 ) ) ⁢ sin ⁢ ⁢ θ ⁡ ( i , j ) ) ⁢ j ′ = j + ( - ( u - ( n + 1 ) ) · sin ⁢ ⁢ θ ⁡ ( i , j ) + ( v - ( m + 1 ) ) ⁢ cos ⁢ ⁢ θ ⁡ ( i , j ) ) M _ ⁡ ( i , j ) = 1 K ⁢ ∑ u = 0 2 ⁢ n + 1 ⁢ ∑ v = 0 2 ⁢ ⁢ m + 1 ⁢ ( W ⁡ ( u , v ) × M ⁡ ( i ′ , j ′ ) ) wherein, W is the definition of linear filtering mask, K is the summation of the mask coefficients in W, M (i, j) is the filtering result at the corresponding point, θ(i, j) is the fingerprint direction angle of each point, (i, j) is the point on the collected fingerprint image M, (i′, j′) is the point obtained in accordance with the point (i, j) filtered by the linear filtering, m, n, u and v are integers.