A non-transitory recording medium storing a computer readable program that causes a computer to perform position aligning, accuracy calculating, and image combining. The position aligning is performing position alignment of other frame images with respect to one reference frame image selected from among multiple frame images that form a dynamic image. The accuracy calculating is calculating an accuracy of the position alignment for each pixel of each of the other frame images. The image combining is combining the reference frame image with the other frame images after the position alignment to generate one composite still image. In the image combining, the computer performs weighting and generates the one composite still image, the weighting being processing of changing a composition ratio between the other frame images for each pixel according to the accuracy calculated by the accuracy calculating.