Image signature matching device

An image signature matching method, comprising:

• matching an image signature of a first image and an image signature of a second image which are generated by a generation method including:
• extracting region features from respective sub-regions of a plurality of pairs of sub-regions in an image;
• for each of the pairs of sub-regions, quantizing a difference value between the region features of two sub-regions forming a pair, wherein when performing quantization, the difference value is quantized to a particular quantization value if an absolute value of the difference value is smaller than a predetermined value;
• and using a collection of elements which are quantization values calculated for the respective pairs of sub-regions as an image signature to be used for discriminating the image, wherein
• the matching the image signature of the first image and the image signature of the second image is performed in such a manner that a weight of an element having the particular quantization value is reduced.

A program for causing a computer to function as,

• a matching unit for matching an image signature of a first image and an image signature of a second image which are generated by a generation method including:
• extracting region features from respective sub-regions of a plurality of pairs of sub-regions in an image;
• for each of the pairs of sub-regions, quantizing a difference value between the region features of two sub-regions forming a pair, wherein when performing quantization, the difference value is quantized to a particular quantization value if an absolute value of the difference value is smaller than a predetermined value;
• and using a collection of elements which are quantization values calculated for the respective pairs of sub-regions as an image signature to be used for discriminating the image, wherein
• the matching unit matches the image signature of the first image and the image signature of the second image in such a manner that a weight of an element having the particular quantization value is reduced.