PURPOSE: To reduce the calculation volume by performing the processing of each picture element of an image by each processing element and operating these processing elements in parallel and determining a generation image by the strength of connection between processing elements.

CONSTITUTION: The processing of each picture element (i, j) of the image is performed by each processing element (10, 11), and these processing elements are operated in parallel, and the generation image is determined by the strength of connection between processing elements. Processing elements (10, 11) are provided in a computer, and strength values of picture elements (i, j) are stored in processing elements (10, 11), and strength values are updated by many consecutive time steps. Each strength value corresponds to a gray level or an image to be generated and corresponds to the strength of one of primary colors of a color image to be generated. Strengths of connection to all processing elements are calculated for different images once. Thus, the calculation volume is reduced.