1. An information processing apparatus for conducting imaging of a three-dimensional image, in which coordinate values are limited to integers, and transformation processing is applied to coordinates (x,y,z) t to create coordinates (x′,y′,z′) t by means of an affine transformation representative of 42 ( x ′ y ′ z ′ ) = A &af; ( x y z ) + ( t 1 t 2 t 3 ), a memory in which a matrix 43 A ′ = ( &it; a 11 ′ a 12 ′ a 13 ′ a 21 ′ a 22 ′ a 23 ′ a 31 ′ a 32 ′ a 33 ′ &it; ) = λ &it; &it; A = ( &it; λ &it; &it; a 11 λ &it; &it; a 12 λ &it; &it; a 13 λ &it; &it; a 21 λ &it; &it; a 22 λ &it; &it; a 23 λ &it; &it; a 31 λ &it; &it; a 32 λ &it; &it; a 33 &it; ) that is obtained by multiplying an affine transformation matrix 44 A = ( &it; a 11 a 12 a 13 a 21 a 22 a 23 a 31 a 32 a 33 &it; ) by &lgr;(≠0), a matrix (t 1,t 2,t 3 ) t, and a shape data are stored; and calculation means for, in transforming the coordinates (x,y,z) t of said shape data into the coordinates (x′,y′,z′) t by means of an affine transformation of the matrix A and the matrix (t 1,t 2,t 3 ) t, reading the matrix A′ and the matrix (t 1,t 2,t 3 ) t from said memory, and calculating x′&equals; (&agr;′ 11 *x&plus;&agr;′ 12 *y&plus;&agr;′ 13 *z )/&lgr;&plus; t 1 ; y′&equals; (&agr;′ 21 *x&plus;&agr;′ 22 *y&plus;&agr;′ 23 *z )/&lgr;&plus; t 2 ; z′&equals; (&agr;′ 31 *x&plus;&agr;′ 32 *y&plus;&agr;′ 33 *z )/&lgr;&plus; t 3 ; and calculating the coordinates (x′,y′,z′) t.