Patent Document ID: 8149464
Application ID: 11221778
Patent Status: 1

Claim One:
1. A clustered-dot screen design method based on human vision characteristics and printer model characteristics, the method comprising: determining positions of a plurality of clustered-dot centers using a predetermined method; and designing a screen via a screen design device by growing specific sub-dots about the plurality of cluster centers using a predetermined clustered-dot screen design algorithm to obtain a designed binary pattern having a minimum cost function between an original input image and a binary pattern through repetitive corrections of the binary pattern according to position information of the plurality of cluster centers, the human vision characteristics of the specific sub-dot growth sequence, and the printer model characteristics, wherein the predetermined algorithm comprises a modified Direct Binary Search (DBS) algorithm that minimizes a cost function φ expressed as: Φ ⁡ ( e ~ ⁡ [ i , j ] , g ⁡ [ i , j ] , x 0 ⁡ [ m ] , y 0 ⁡ [ m ] ) = ∑ all ⁡ ( i , j ) ⁢ ⁢ e ~ ⁡ [ i , j ] 2 + ∑ ( i , j ) ∈ G 0 ⁢ m MIN ⁢ ( ( i - x 0 ⁡ [ m ] 2 ) + ( j - y 0 ⁡ [ m ] 2 ) ) - ∑ ( i , j ) ∈ G 1 ⁢ m MIN ⁢ ( ( i - x 0 ⁡ [ m ] 2 ) + ( j - y 0 ⁡ [ m ] 2 ) ) ⁢ ⁢ m = 0 , … ⁢ , M - 1 where (x 0 [m], y 0 [m]) for m=0,. .. , M−1 represent coordinates of the plurality of cluster centers, G 0 represents a set of coordinates of black sub-dots grown about the cluster centers, G 1 represents a set of coordinates of white sub-dots grown about the cluster centers, g[i,j] represents the binary pattern, and {tilde over (e)}[i,j] represents a visual difference value between an input image and a print out of the input image.