1. An object detection system comprising a terminal device and a server, the terminal device including an imaging device configured to capture images, a first image processing device configured to receive the images from the imaging device and detect from the images an image that contains a target to be detected, and a first communication device configured to transmit data to and receive data from the server, and the server including a second communication device configured to transmit data to and receive data from the terminal device, a second image processing device configured to recognize the target to be detected from the image received from the terminal device, and a storage device configured to store data on the recognized target to be detected, wherein the terminal device is configured to execute a process of, with the first image processing device, detecting from the captured images a candidate image that contains the target to be detected on the basis of a first evaluation criterion, and a process of, with the first communication device, transmitting to the server the candidate image detected on the basis of the first evaluation criterion, and the server is configured to execute a process of, with the second communication device, receiving the candidate image, a process of, with the second image processing device, recognizing from the candidate image the target to be detected contained in the candidate image on the basis of a second evaluation criterion that is different from the first evaluation criterion, and a process of storing an image of the target to be detected and the candidate image into the storage device.