| 摘要 |
PURPOSE:To execute natural normalization while holding the balance of the whole image even in the case of an irregularly deformed pattern such as a hand-written character in an image non-linearity normalizing device to be used for the preprocessing of image correlation calculation. CONSTITUTION:A spatial density measuring part 5 finds out a local spatial density function h(Xi, Yj) as the product of the inverses of line intervals in both X and Y directions based upon a two-dimensional pattern f(Xi, Yj) obtained by supposing that infinite dots are arrayed in the same direction in any of vertical and horizontal directions on an infinite plane. The sampling interval (deltai, epsilonj) of a new sampling point (X'i, Y'j) are determined by X-axis and Y-axis coordinate conversion calculating parts 8, 9 so that the product of the spatial density function (Xi, Yj) of the two-dimensional pattern f(Xi, Yj) and the sampling interval (deltai, epsilonj) is fixed, a normalized sampling value for the new sampling point (X'i, Y'j) is found out by resampling or recalculation from the twodimensional pattern f(Xi, Yj). |
