Data interpolation method and its device and storage medium

PROBLEM TO BE SOLVED: To reduce filter function coefficients and to reduce requested memory capacity by constructing a look up table only by means of a necessary coefficients against a specified resampling ratio before the start of interpolation. SOLUTION: A logic control unit 103 sets up calculations for sampling increments stepx and stepy and maximum cycle counts maxx and maxy. An index generator 105 starts generating whole coefficients in horizontal kernel, and generates the indexes of '0' to maxx-1. A fraction generator 107 generates all fractions. All the coefficients are written into a kernel coefficient look up table(LUT) 111. For generating all the coefficients in a vertical kernel, a similar processing is executed. All the coefficients are written into coefficient LUT 109. A coefficient reading circuit 115 interpolates the source pixel and reads appropriate coefficients from LUT 109 and 110