DATA EXTRACTING METHOD, DATA EXTRACTING DEVICE AND PROGRAM SUPPLYING MEDIUM FOR SUPPLYING DATA EXTRACTING PROGRAM

摘要

PROBLEM TO BE SOLVED: To perform more precise edge detection by allowing the value of a spatial frequency component to cut out only elements discriminated by 1st and 2nd thresholds which are different from each other among respective elements of an input n-dimensional data group.;SOLUTION: An edge enhancing part 11 calculates a difference image Δf (x, y) that enhances the edge of an original image f (x, y). And an edge pixel cutting out part 12 cuts out edge pixels from the image Δf (x, y). In such a case, optional positive threshold and negative threshold as thresholds for deciding whether the change of density difference in the edge pixels is sufficiently large or whether spatial frequency components are sufficiently large are provided in edge detection processing. Then, only parts which are equal to or more than the 'positive threshold or are equal to or less than the negative threshold are cut out as an edge part. Further, an edge searching part 13 calculates an edge image h (x, y) being an n-dimensional extraction output data group form a binary image g (x, y) showing the cut out edge positions.;COPYRIGHT: (C)2000,JPO