Patent ID: 8149464
Filing Date: 2012-04-03
Classification: H04N

Abstract:
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: 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.