PURPOSE: To set and encode the image attribute and the area in the transmitting image with a compression encoding system suitable for respective image attributes to transmit them to the opposite party equipment.

CONSTITUTION: The image attribute and area of image data read from an original part 101 are setby an image attribute and area setting part 102. Corresponding to respective image attributes, optimum code data between binary code data from a threshold processing part 105 and multilevel code data from a multilevel encoding processing part 103 are selected and outputted. When changing (switching) the encoding system, an encoding system switching code is reported to the opposite party equipment by generating and transmitting the encoding system switching code such as a CCD(Change Codebook) from an encoding system switching code output part 109.