In order to detect the foreground without being affected by reflected light from the shadow of an object or the background and so on, in both indoor and outdoor environments, the image processing method includes a step of generating first foreground likelihood from a visible light image, a step of generating second foreground likelihood from a depth image in which the same object is captured as that in the visible light image, a step of generating reliability of the depth image using at least the visible light image and the depth image, and a step of determining foreground likelihood of the object based on the first foreground likelihood and the second foreground likelihood, using the reliability of the depth image as a weight.