Data processing method, recording medium and data processing apparatus

A recording medium for recording image data readable by a computer, wherein:

• said image data has coordinate data of a reference point for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, and differential data between coordinates of each of said vertexes and coordinates of said reference point.

A data processing apparatus comprising:

• storage means which can store coordinate data of a reference point in a type of floating point number for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, differential data of a difference between coordinates of each of said vertexes and coordinates of said reference point in a type of integer, and scale value data for providing a reference of magnitude of said differential data in a type of floating point number;
• and
• operation control means for receiving said differential data read out from said storage means, type-converting said received differential data into floating point numbers, multiplying said type-converted differential data by said scale value data, and outputting a multiplication result as expanded differential data.

A data processing method comprising the steps of:

• inputting coordinate data of a reference point in a type of floating point number for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, and differential data of a difference between coordinates of each of said vertexes and coordinates of said reference point in a type of floating point number;
• and
• carrying out affine transformation upon said inputted coordinate data of said reference point while linear transformation in which parallel displacement is excluded from said affine transformation is carried out upon coordinate data of said vertexes sharing said reference point.

A recording medium for recording a program readable by a computer, wherein:

• said program makes said computer input coordinate data of a reference point in a type of floating point number for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, and differential data of a difference between coordinates of each of said vertexes and coordinates of said reference point in a type of floating point number;
• and said program makes said computer carry out affine transformation upon said inputted coordinate data of said reference point while linear transformation in which parallel displacement has been excluded from said affine transformation is carried out upon coordinate data of said vertexes sharing said reference point.

A data processing apparatus comprising:

• storage means which can store coordinate data of a reference point in a type of floating point number for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, and differential data of a difference between coordinates of each of said vertexes and coordinates of said reference point in a type of floating point number;
• and
• operation means for carrying out affine transformation upon said coordinate data of said reference point read out from said storage means while linear transformation in which parallel displacement is excluded from said affine transformation is carried out upon coordinate data of said vertexes sharing said reference point.

A recording medium for recording a program readable by a computer, wherein:

• said program makes said computer input coordinate data of a reference point in a type of floating point number for a set of vertexes of a plurality of polygons approximating a three-dimensional shape of an image, and differential data of a difference between coordinates of each of said vertexes and coordinates of said reference point in a type of floating point number;
• and said program makes said computer carry out perspective transformation upon said vertexes of said plurality of polygons in such a manner that perspective transformation based on division using a geometric relationship of similarity is carried out upon said inputted coordinate data of said reference point so as to obtain perspective-transformed coordinate data of said reference point, while approximate calculation for said perspective transformation is carried out upon said inputted coordinate data of said vertexes other than said reference point on the basis of Maclaurin series expansion using said perspective-transformed coordinate data of said reference point so as to obtain perspective-transformed coordinate data of said vertexes.