This invention provides an image processing system and image processing method which can promote efficient use of a memory by vectorizing all data of a representative object and, for the same or similar object, referring to the vectorized representative object and using difference data and also convert the same or similar objects at once by editing only the representative object. Input image information is vectorized. The vector data of a representative object is stored. Identity between a target object and the representative object is determined. If the two objects are identical, property information containing information about the reference destination of the vector data of the representative object is stored in place of the vector data of the target object.