An object tracking method comprising: detecting a target object in a first-type input image that is based on light in a first wavelength band; tracking the target object in the first-type input image based on detection information of the target object and by selecting a first tracker corresponding to a measured quality of the first-type input image from among multiple trackers (611, 613, 615), wherein the first tracker is trained using images that are captured using light of the first wavelength band and that have a quality that is specific for the first tracker, and providing the first-type input image to the first tracker; measuring a reliability of the first-type input image by comparing the first-type input image to at least one image stored in a first database, DB; and when the reliability of the first-type input image is lower than a first threshold, controlling at least one of a light source and camera and switching a first modality referring to an operation associated with the first wavelength band to a second modality referring to an operation associated with a second wavelength band different from the first wavelength band to track the target object in a second-type input image based on light in the second wavelength band using the detection information and by selecting a second tracker (613, 615) corresponding to a measured quality of the second-type input image from among multiple trackers (611, 613, 615), wherein the second tracker (613, 615) is trained using images that are captured using light of the second wavelength band and that have a quality that is specific for the second tracker (613, 615), and providing the second-type input image to the second tracker (613, 615). detecting a target object in a first-type input image that is based on light in a first wavelength band; tracking the target object in the first-type input image based on detection information of the target object and by selecting a first tracker corresponding to a measured quality of the first-type input image from among multiple trackers (611, 613, 615), wherein the first tracker is trained using images that are captured using light of the first wavelength band and that have a quality that is specific for the first tracker, and providing the first-type input image to the first tracker; measuring a reliability of the first-type input image by comparing the first-type input image to at least one image stored in a first database, DB; and when the reliability of the first-type input image is lower than a first threshold, controlling at least one of a light source and camera and switching a first modality referring to an operation associated with the first wavelength band to a second modality referring to an operation associated with a second wavelength band different from the first wavelength band to track the target object in a second-type input image based on light in the second wavelength band using the detection information and by selecting a second tracker (613, 615) corresponding to a measured quality of the second-type input image from among multiple trackers (611, 613, 615), wherein the second tracker (613, 615) is trained using images that are captured using light of the second wavelength band and that have a quality that is specific for the second tracker (613, 615), and providing the second-type input image to the second tracker (613, 615).