| 摘要 |
PURPOSE:To attain the reduction of a binary picture compensating the disadvantage of the projection method such as missing of a thin line by detecting it that a pattern of a reference picture element is a pattern requiring the predetermined correction with respect to an output value (projection) of the projection method around a noted picture element, and applying a positive or a negative correction value. CONSTITUTION:For example, 3X3 block data D1.1-D3.3 from a line buffer 1 as shown in figure (b) are inputted to a projection value calculator 2 and a correction value calculator 3. The projection value calculator 2 calculates a projection value sum by using matrix values a1.1-a3.3 as shown in figure (c) in a memory 5 according to equation I. The correction value calculator 3 uses the block data D1.1-D3.3 from the buffer 1 and the reduced picture element obtained already as reference picture element data and outputs a correction value mod. Then a correction projection value sum + mod is obtained by an adder 7, a comparator 4 binarizes the value of a threshold level memory 6 to output 1 or 0. Thus, in the case of a predetermined specific pattern, a positive or negative correction is applied to the projection value to prevent missing of a thin line. |
