1. An in-vehicle device installed in a vehicle comprising: a camera configured to capture images of surroundings of the vehicle; and a correction unit configured to correct alignment information that represents alignment of the camera, the correction unit comprising: a sampling unit configured to repeat a sampling process of sampling N state vectors each of which includes, as elements, a position of the camera with respect to a reference point of the vehicle, a posture of the camera, a width of a lane on which the vehicle is located, a position of the vehicle in a width direction of the lane, and an orientation of the vehicle with respect to a direction of the lane; an update unit configured to update the N state vectors sampled by the sampling unit as much as an amount based on a predetermined dynamics model or a random amount; a weight calculation unit configured to, for each of the N state vectors updated by the update unit, when respective values of individual elements of the state vector are true, calculate a shape of a lane mark to be included in an image captured by the camera and calculate, as a weight of the state vector, a degree of similarity between the calculated shape of the lane mark and a shape of a lane mark in the image captured by the camera; and an alignment information generation unit configured to estimate current alignment of the camera on the basis of the N state vectors, the respective weights of which are calculated by the weight calculation unit, and the respective weights of the N state vectors or on the basis of the N state vectors sampled by the sampling unit and generate the alignment information, which represents the estimated alignment, wherein, in the sampling process for the second and subsequent times, the sampling unit samples new N state vectors on the basis of the respective weights of the N state vectors calculated by the weight calculation unit, such that an image displayed within the vehicle is updated on the basis of the alignment information generated by the correction unit.