1. An information extraction computer device for extracing information from a picture by mapping, comprising: converting means for detecting points in a picture on a spherical surface by physically detecting the points, determining coordinates of the points and storing the coordinates; mapping means for mapping, according to a polar transformation mapping function, the points in the picture into great circles on the spherical surface, each of said great circle being defined by an intersection between the spherical surface and a mapping plane which is perpendicular to a radius connecting a center of a sphere defined by the spherical surface and the respective point on the spherical surface, and which mapping plane includes the center of the sphere; and information extraction computation means for extracting information from the picture on the spherical surface on the basis of mapping function data of coordinate values of the points obtained by said mapping means.