PURPOSE: To improve the quality of an image for a low density part such as a natural image and an image at a high density part such as a character part by applying UCR processing to each color signal so as to generate newly each density signal and recording the signal by 5 kinds of recording means based on each signal.

CONSTITUTION: Each of received R, G, B signals is converted respectively into each of C, M, Y signals by a color conversion section 1 at first and converted respectively into C', Y', K1, K2 signals by a UCR(under color reduction) section 3. As the UCR processing implemented in this case, at first, an under color part of each of the C, M, Y signals is detected, then the detected under color part is divided into a high density component and a low density component in a predetermined ratio and a signal corresponding to each component is generated. Finally 5 kinds of recording means of a recording section 7 are used to record the signals corresponding to each of the C', Y', K1, K2 signals.