Disclosed herein are an image processor, an ultrasonic imaging device, and an image processing method. The image processor includes a signal input unit configured to receive an input signal on a channel, a weighting coefficient database configured to store a weighting coefficient wherein the weighting coefficient is part of a weighting coefficient subgroup, and a processor configured to select the weighting coefficient subgroup from the weighting coefficient database, and convert the input signal by selecting and using the weighting coefficient from the weighting coefficient subgroup.