1. An image processing apparatus comprising: unconscious expression parameter storing means for storing an unconscious parameter specifying an unconscious facial expression, the unconscious facial expression being applied to a model automatically at a periodic rate without requiring user input to apply the unconscious facial expression; conscious expression parameter storing means for storing a conscious parameter specifying a conscious facial expression, the conscious facial expression being applied to the model after being specified and customized by a user, the user customizing the conscious facial expression by instructing the apparatus to execute a function haying a plurality of user-specified parameters defining attributes of a specific conscious facial expression; parameter updating means for updating the conscious parameter to include animation features defined by the user-specified parameters; mixing means for generating face model data by mixing the unconscious expression parameter and the updated conscious expression parameter; and rendering means for rendering a facial expression on the basis of the face model data.