| 摘要 |
PURPOSE:To reduce the capacity of a conversion coefficient table and to miniaturize a product sum arithmetic circuit by forming the conversion coefficient table for each block based on a fact that the control point of a Bezier function curve can be calculated from four control points of a non-uniform B spline function curve. CONSTITUTION:A conversion coefficient table 23 stores the conversion coefficients corresponding to each knot vector every (4X4) blocks. A product sum circuit consists of 4 units of multipliers 24a - 24d and an adder circuit 25. A control real distributor 21 takes out four control points corresponding to the blocks of conversion coefficients read out of the table 23 among those control points of a non-uniform B spline function curve. Then the distributor 21 supplies those four control points to the product sum circuit to perform the operation to the blocks of the read coefficients. Thus the control point of a Bezier function can be calculated from four control points of the non- uniform B spline function curve. Therefore the undesired coefficients can be eliminated constituting the table 23 for each block. As a result, the capacity of the table 23 is reduced and the number of multipliers and adders can be decreased in the product sum circuit and the circuit is miniaturized. |
