Image processing device, imaging device, image processing method, and non-transitory computer readable medium

An image processing method, comprising:

• a step, executed by a processor, of acquiring a taken image in which a subject is imaged,
• a step, executed by the processor, of generating a smoothed image by smoothing the taken image;
• a step, executed by the processor, of acquiring a noise image that represents noise included in the taken image;
• a step, executed by the processor, of generating a smoothed noise image by smoothing the noise image with the smoothing strength used for smoothing the taken image;
• a step, executed by the processor, of extracting a difference noise component from a difference between the noise image and the smoothed noise image;
• a step, executed by the processor, of adding the difference noise component to the smoothed image;
• a step, executed by the processor, of acquiring a distance map that represents a distribution of distances on a pixel-by-pixel basis or a region-by-region basis in the taken image;
• and
• a step, executed by the processor, of combining the taken image with the smoothed image on the basis of the distance map, and generating an output image.