PURPOSE: To improve the discrimination effect of an additional picture without deleting a transmission picture even with a large additional picture by companding properly the transmission picture so as to insert the processed picture to an area of the additional picture.

CONSTITUTION: Paper on which an additional picture 1 is drawn is placed on a scanner 7, and when an operation display section 12 selects the image registration mode, a CPU 8 reads the picture 1 to segment picture data of an additional image area. Then the CPU 8 transfers the segmented picture data to a plotter 11 and outputs it. When the operator enters a registration number, a coding decoding section 13 compresses and encodes the picture, the result is registered in a ROM 9. Then the transmission original is set and the registration number of the additional picture is received to command transmission start, then the additional picture is decoded and stored in a RAM 10. Then the transmission original is read and expanded/compressed at a predetermined magnification by a picture processing section 4 and synthesized so as to be inserted in a predetermined area of the additional picture and sent through coding compression.