An image processing apparatus includes: a processor configured to execute: acquiring image data； generating a first interpolation image data corresponding to light in a red wavelength band, a second interpolation image data corresponding to light in a green wavelength band, a third interpolation image data corresponding to light in a blue wavelength band, and fourth interpolation image data corresponding to narrow band light； calculating a ratio of a pixel value of the fourth interpolation image data to a pixel value of the second interpolation image data for each region including one or a plurality of pixels； extracting a pixel of the fourth interpolation image data in the region where the calculated ratio exceeds a predetermined threshold value； generating a composite image data based on the pixel value of the extracted pixel and the second or the third interpolation image data； and generating color image data.
