PURPOSE: To obtain a sharp transmission picture with less picture quality deterioration without transmission of excess space by discriminating a reduction ratio of a transmission image so that the size of a valid part of an original is nearly equal to a size of recording paper.

CONSTITUTION: The transmitter is made up of a read original length measurement section 2 measuring a length of an original image read by a read section 1, a space original length measurement section 3 measuring the length of the continuous space occupied to a tip/tail end of an original image, a read original width measurement section 5 measuring the width of the original image, a space original width measurement section 6 measuring the width of a continuous space shared to a left/right end of the original image, a recording paper length discrimination section 8 and a recording paper width discrimination section 9 discriminating the length and the width of recording paper mounted on a receiver and a reduction ratio discrimination section 10 discriminating a reduction ratio covering a valid original length excluding a space from the length of the recording paper and a reduction ratio covering a valid original width excluding a space from the width of the recording paper.