PURPOSE: To obtain a compression mode for letter and image date by a method in which even specific additional information, besides the coordinate value of the points provided on a letter border and m-order curve approximation between the adjacent two points, is used as memory data and the smoothness of the letter border is faithly coded and stored.
CONSTITUTION: For a bit pattern data obtained by dot-decomposing a letter image into a matrix form, the position of borders on X- and Y-coordinates is obtained by application of a border extraction treatment. The point P is set on the border and the border is divided into the sections of single-valued function with X as a variable to obtain block B properly for each. Any one block B is further divided into plural segments Si, and in terms of the m-order curve, fi(x)=yi+ΣAiJ(x-xi)j, passing through the start point Pi(xi, yi) of each segment Si, the coefficient Aij(j=1Wm) of (n-1) set is obtained. The coefficient Aij and the coordinate value (xi, yi)(i=1Wn) of the point Pi are stored as the border data corresponding to the block.
TAKASHIMA MASATAKE
FUKUDA SHINICHIROU
SHIBATA HIROYUKI
| JPS5579154A | 1980-06-14 |