An endoscope image processing device includes a processor including hardware programmed to: enlarge or reduce multiple color component images constituting a normal light image, and a narrow-band light image； generate a blended image by synthesizing one of the enlarged or reduced color component images and the enlarged or reduced narrow-band light image； and generate a color superimposed image by synthesizing the blended image and the other enlarged or reduced color component images. The processor is programmed to replace some of pixels of the one color component image with corresponding pixels of the narrow-band light image such that distribution of pixels of the one color component image and pixels of the narrow-band light image is substantially uniform over the blended image.
