A method for an image capturing device includes: acquiring a first image of a target object; extracting coordinate information of a first 2D key point corresponding to the target object; acquiring a second image of the target object; acquiring coordinate information of a second 2D key point in the second image according to the coordinate information of the first 2D key point, the first 2D key point and the second 2D key point being the same key point in the target object; acquiring coordinate information of a 3D key point corresponding to the target object, the 3D key point being a key point obtained after a triangulation operation; and determining camera posture information of the second image according to the coordinate information of the first 2D key point, the coordinate information of the second 2D key point, the coordinate information of the 3D key point, and a 3D-2D projection.