One aspect of the present invention thinning-reads pixel signals from the multiple pixels according to a thinning pattern from an image pickup element, or extracts pixel signals from the multiple pixels according to the thinning pattern from a color image that is read from the image pickup element and corresponds to the color filter array, and acquires a thinned color image. Then, moving image data is generated on the basis of the thinned color image. Adoption of the thinned color image as a target image to be subjected to moving image processing can facilitate reduction in processing time per frame, and prevent the frame rate from decreasing. Furthermore, thinning-reading pixels from the image pickup element can facilitate reduction in time of reading an image from the image pickup element.