Black inverted noises in a white background due to resolution correction are reduced by an image processing apparatus which carries out image modification processing to invert at least a portion of a binary converted signal obtained from binary conversion of an image signal. An image signal S1 is respectively input to resolution correction means 201 and 202 using different correction amounts. The signal is then input to selecting means 310 from the both resolution correction means. The signal output from the selecting means is input to binary conversion means 400 and a signal S2 output therefrom is input to image modification processing means 500. when image modification processing has been instructed, a control signal CNT1 is input to the selecting means 310 and the selecting means output a signal with weak resolution correction from the resolution correction means 202 using a small correction amount.