1. An image processing apparatus comprising: an HDR (High Dynamic Range) processing unit inputting images that have been picked up while exposure control that changes an exposure time is being carried out with a predetermined spatial period and a predetermined temporal period on pixels that compose an image sensor, and carrying out image processing, wherein the HDR processing unit: generates a first combined image by combining pixel values of a plurality of images with different sensitivities generated by an interpolation process using a plurality of images that have been picked up consecutively; generates a second combined image by combining pixel values of a plurality of images with different sensitivities generated by an interpolation process that uses a single picked-up image; and generates an HDR (high dynamic range) image by executing a pixel value blending process on the first combined image and the second combined image in accordance with a blending ratio calculated in accordance with movement detection information.