PURPOSE: To shorten the time required for conversion of the picture element density when the size or the image resolution of a facsimile image is changed.

CONSTITUTION: When the paper size and the image resolution are not coincident with those of the opposite party equipment, the coded data stored in a coded data storing part 105 are decoded by a decoding processing part 110. These coded data undergo the conversion of the picture element density so as to secure the coincidence with the paper size and the image resolution of the opposite party equipment. Then the decoded data are coded again and stored in the coded data storing part 105 and transmitted through a circuit control part 106. At the same time, the line or page synchronizing signals are shortened compared with a reception/print mode before they are inputted to a decoding processing part 110, a picture element density conversion processing part 111, and a coding processing part 104 respectively.