Passenger information detection device and program

A passenger information detection device comprising:

• an acquisition unit that acquires an image imaged by an imaging device that is provided in an interior space of a vehicle to image a passenger seated on a seat and a detection value of a load sensor provided on the seat;
• a first calculation unit that calculates first information that is information including a position of a face of the passenger from the image;
• and
• a second calculation unit that calculates second information that is information on a body size of the passenger based on the first information and the detection value,
• wherein the second calculation unit calculates a center of gravity of a distributed load acting on the seat based on the position of the face, and corrects the detection value based on a relationship between the center of gravity and a position of the load sensor,
• the first calculation unit further calculates a position of an upper extremity of the passenger, and
• the second calculation unit determines whether the upper extremity is in contact with a fixed object other than the seat based on the position of the upper extremity, and in a case where it is determined that the upper extremity is in contact with the fixed object, the second calculation unit further corrects the detection value to become larger.