Comparison device and comparison method

A comparison device comprising:

• a processor;
• a storage unit;
• and
• a display unit,
• wherein the processor
• compares an imaged face image obtained by imaging a face of a comparison target person to a registered face image registered in the storage unit,
• determines whether or not the comparison score is equal to or greater than Th2 (Th2<Th1), in a case where a comparison score indicating a result of the comparison is equal to or smaller than Th1 and it is determined that the comparison target person in the imaged face image is not a subject of the registered face image,
• calculates a partial score indicating similarity between the imaged face image and a portion of the registered face image in a case where the comparison score is equal to or greater than Th2, and
• performs processing of emphasizing a portion corresponding to the partial score on at least one of the imaged face image and the registered face image and displays the image subjected to the processing in the display unit, in a case where the calculated partial score is equal to or smaller than Th3.