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 wherein the HDR processing unit generates the HDR image by executing the pixel value blending process where the blending ratio of the second combined image is raised for a pixel position where the movement detection information shows that there has been movement and the blending ratio of the first combined image is raised for a pixel position where the movement detection information shows that there has been no movement.