This image feature extraction device extracts, from an image, an image feature that makes it possible to adjust the balance between identification capability and robustness, which are the scales of the capability of determining identity of images. This image feature extraction device executes hierarchical quantization to calculate quantization indexes of a plurality of hierarchies in accordance with a previously defined hierarchical quantization method for each quantization target region of an image, and outputs a hierarchical quantization index code, which is an encoding allowing unique specification of the quantization indexes of the respective hierarchies of each quantization target region.