An image processing apparatus creates a basic-structure component image representing an image that an input image except edge is smoothed while preserving the edge in the input image; and creates a detail component image representing an image that the basic-structure component image is subtracted from the input image. Subsequently, the image processing apparatus decomposes the detail component image into a plurality of frequency-band images through multiresolution transform processing, and performs noise removal on the obtained frequency-band images. After that, the image processing apparatus performs inverse multiresolution transform processing of combining the noise-removed frequency-band images, thereby creating a noise-removed detail-component image.