Image processing device and image processing method

An image processing method performed by an image processing device, the method comprising:

• analyzing a first image sequence including a plurality of images obtained by imaging a first region to detect a first object that appears in any one of the images of the first image sequence, and analyzing a second image sequence including a plurality of images obtained by imaging a second region different from the first region to detect a second object that appears in any one of the images of the second image sequence;
• generating a first object feature amount for tracking the first object and a second object feature amount for tracking the second object;
• tracking the first object in a time direction within the first image sequence using the first object feature amount to output a tracking result including a plurality of values of the first object feature amount as a first object tracking history, and tracking the second object in the time direction within the second image sequence using the second object feature amount to output a tracking result including a plurality of values of the second object feature amount as a second object tracking history;
• detecting whether or not the first object feature amount has changed using the first object tracking history to output a detection result as a first feature-amount-change detection result, and detecting whether or not the second object feature amount has changed using the second object tracking history to output a detection result as a second feature-amount-change detection result;
• extracting a value of the first object feature amount from the first object tracking history for an image determined to have no change in the first object feature amount to output the extracted value of the first object feature amount and the first object tracking history as a first tracking-history extraction result, and extracting a value of the second object feature amount from the second object tracking history for an image determined to have no change in the second object feature amount to output the extracted value of the second object feature amount and the second object tracking history as a second tracking-history extraction result;
• and
• determining whether or not the first object and the second object are identical using the first tracking-history extraction result and the second tracking-history extraction result.