An image processing apparatus is provided which includes: an image obtaining unit for obtaining a mosaic image by an image sensor having at least four kinds of filters with different spectral sensitivities, one of the at least four kinds of filters being used for each pixel; and an image processing unit for generating a color image such that intensity information at a position of each pixel, the intensity information corresponding to a number of colors determined by the spectral sensitivities of the filters, is computed for all pixels, from the mosaic image obtained by the image obtaining unit. In a color filter arrangement of the image sensor of the image obtaining unit, filters possessed by pixels arranged in a checkered manner in half of all the pixels have at least some spectral characteristics having a strong correlation with the spectral characteristic of luminance. The image processing unit calculates estimated intensity values of colors possessed by the pixels arranged in the checkered manner at each pixel and calculates a luminance value of each pixel on a basis of the estimated intensity values.
