The method produces, from a first image, a second image with sparse coding. The method produces, from the first image, a processing intermediate image having a pixel value distribution that a difference among pixel values in a region of the intermediate image is equal to a DC component in a corresponding region of the first image, performs a first process of acquiring, using an AC component in a first region of the intermediate image and a basis produced by dictionary learning, an AC component in a second region, performs a second process of acquiring a difference among pixel values in the second region as a DC component in a corresponding region of the second image, and repeats the first and second processes with changing a position of the first region in the intermediate image to acquire DC components in regions of the second image.