1. An image processing device comprising: a processor configured to function as: a local feature amount calculation unit configured to detect feature points in each of a first image and a second image and calculates, for each of the feature points, a local feature amount of the feature point, based on a peripheral region of the feature point, the peripheral region including the feature point; a correlation identifying unit configured to specify, based on the local feature amount of each of the feature points of the first image and the local feature amount of each of the feature points of the second image, a correlation between the feature point of the first image and the feature point of the second image; a partial region detection unit configured to detect partial regions including the first image; and a matching unit configured to determine, for each of the partial regions, whether or not an object in the first image and an object in the second image are the same or similar based on the feature points included in the partial region and the feature points of the second image which corresponds to each of the feature points in the partial region; wherein the partial region detection unit detects partial regions, based on a first scale value information group and a second scale value information group, the first scale value information group being a set of pieces of size information, of peripheral regions corresponding to each of the feature points of the first image, and the second scale value information group being a set of pieces of size information of peripheral regions corresponding to each of the feature points of the second image.