Similarity calculation method and device

A similarity calculating apparatus adapted for determining similarity between two input vectors, comprising:

• a distance calculating unit for performing a distance calculation between the two input vectors in a component-wise hierarchical manner,
• a threshold value comparing unit for comparing an integrated value of distances calculated incrementally for hierarchically higher-order components of the two vectors-by the distance calculating unit with a predetermined threshold value,
• a control unit for controlling the distance calculation in accordance with a result by the threshold value comparing unit, and
• an output unit for outputting, as the similarity, the integrated value of distances calculated up to the last components of the two vectors,
• wherein,
• the control unit is operative so that in the case where integrated value of distances calculated up to a certain component order is above the threshold value as the result of comparison by the threshold comparing unit, a control is performed so as to truncate the distance calculation.

A computer readable medium comprising instructions which when executed by a computer system causes the computer to implement a program for allowing a computer to execute similarity calculation processing for determining similarity between two input vectors, the program comprising:

• calculating a distance between the two input vectors in a component-wise hierarchical manner,
• comparing integrated value of distances calculated incrementally for hierarchically higher-order components of the two vectors with a predetermined threshold value,
• controlling the distance calculation at the distance calculation step in accordance with a result of the threshold value comparison, and
• outputting, as the similarity, integrated value of distances calculated up to the last components of the two vectors,
• wherein,
• in the case where the integrated value of distances calculated up to a certain component order is greater or equal to the threshold value, control is conducted in such a manner to truncate the distance calculation.

A computer readable medium adapted so that a program for allowing a computer to execute similarity calculation processing which determines similarity between two vectors is recorded,

• the program including:
• performing a distance calculation between the two input vectors in a component-wise hierarchical manner,
• comparing an integrated value of distances calculated incrementally for hierarchically higher-order components of the two vectors with a predetermined threshold value set,
• controlling the distance calculation in accordance with a result at the threshold value comparison, and
• outputting, as the similarity, integrated value of distances calculated up to the last components of the two vectors,
• wherein,
• in the case where the integrated value of distances calculated up to a certain component order is above the threshold value, control is conducted in such a manner to truncate the distance calculation.