To perform progressive mesh segmentation suitable of interactive applications a high speed with high precision.An image processing device 10 includes an image information input unit 1 for inputting three-dimensional image information to be processed in the format of an incidence graph, an incidence graph evaluation unit 2 for evaluating and sorting the edges of the input incidence graph, an image region mesh growing unit 3 for extracting pairs of image regions sandwiching edges in the sorted order and evaluating and performing mesh growing thereof based on a statistical processing algorithm, and a minute node processing unit 4 for processing minute regions remaining as a result of the image region mesh growing.