| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a high-precision approximation while reducing the load of calculation when discrete data obtained by patch images are interpolated by using an approximate formula. <P>SOLUTION: When an approximate formula is to be determined, the amount of variation of a density change rate is derived on the basis of the respective output values of a plurality of patch images set stepwise to different densities, and the amount of variation of the density change rate is divided into curve approximate areas A to F and line approximate areas (a) to f in accordance with the amount of variation of the density change rate. In particular, the curve approximate areas are set with area widths corresponding to the variations of the density change rate in sections on both sides of reference points P<SB>1</SB>to P<SB>6</SB>which are the densities of patch images, and line approximate areas are set so as to interpolate the curve approximate areas. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
