1. An image processing device comprising: an image signal input portion for inputting an image signal of images obtained by medical equipment having an imaging function; an image dividing portion for dividing each of a plurality of images into a plurality of regions, respectively, the plurality of images being representative of the image signal; a feature vector calculation portion for calculating a plurality of feature vectors in each of the plurality of regions; a first cluster classifying portion for generating a first plurality of clusters in a first feature space on the basis of a first feature vector of the plurality of feature vectors and the occurrence frequency of the first feature vector in the plurality of feature vectors and for classifying the first plurality of clusters into any of a plurality of classes, respectively, the first feature space indicating chromaticity of the image; a second cluster classifying portion for generating a second plurality of clusters in a second feature space on the basis of a second feature vector of the plurality of feature vectors and the occurrence frequency of the second feature vector in the plurality of feature vectors and for classifying the second plurality of clusters into any of the plurality of classes, respectively, the second feature space indicating variation in the chromaticity of the image; and a cluster division portion for carrying out division processing such that, when it is detected that the second feature vectors calculated in different regions included in the plurality of regions belong to different clusters respectively in the second plurality of clusters and that the first feature vectors calculated in the different regions included in the plurality of regions belong to one cluster in the first plurality of clusters, the division processing is carried out with respect to the one cluster.