1. An image processing device comprising: an image sequence acquisition section that acquires an image sequence that includes a plurality of images; and a processing section that performs an image summarization process that deletes some of the plurality of images included in the image sequence acquired by the image sequence acquisition section to acquire a summary image sequence, the processing section selecting a reference image and a determination target image from the plurality of images, and determining whether or not the determination target image can be deleted based on results of a process that utilizes deformation information about the reference image and the determination target image, and a process that utilizes a structuring element that corresponds to an attention area, the processing section implementing the process that utilizes the structuring element by performing an erosion process that utilizes the structuring element on the determination target image to calculate a coverage-requiring area, the processing section implementing the process that utilizes the deformation information by performing a process that deforms the coverage-requiring area or the reference image based on the deformation information about the reference image and the determination target image, and the processing section determining that the determination target image can be deleted when the deformed coverage-requiring area is included within the reference image or when the coverage-requiring area is included within the deformed reference image.