| 摘要 |
PURPOSE:To make overall scan to find the start point of scan unnecessary and to shorten a time required for the extraction processing of a feature point, by extracting the feature point of an image element from the differential value of a remarked image element and that of its peripheral image element. CONSTITUTION:Assuming the remarked image element as F, each coordinate value of eight image elements in the neighborhood is expressed as shown in figure as a peripheral coordinate in an x-axis direction. In such a case, by considering eight unit vectors in which a unit vector U is defined in a left turn at an interval of 45 deg. and performing the first-order differentiation of an image F (x, y), it is possible to find the directional component Uk(k=0-8) of the image element in the coordinate point (x, y) of the image F (x, y). And by finding the coordinate point Uknot equal to 0, it is set as the remarked image element, and an image element position of the coordinate point Uk=0 is checked for the positions of the eight image elements in the neighborhood of the remarked image element, and the vector can be obtained by connecting the image elements being confronted with each other and with the minimum distance between them. |
