An image processing device replaces pixel values received from an imaging device that includes multiple types of pixels being arranged in a first pixel arrangement to detect different wavelength ranges of light, with pixel values of pixels in a second pixel arrangement different from the first pixel arrangement, by determining whether there is an edge indicating a direction along which pixels having a smaller change in pixel values are aligned that are positioned around a target pixel to be interpolated, and have a same color as the target pixel after replacement; and interpolating, if an edge is determined, a pixel value of the target pixel using the pixel values of the pixels along the direction of the edge, or if no edge, the pixel value of the target pixel using pixel values of pixels along a direction of another edge detected based on brightness around the target pixel.