Visual Tilt Correction for Vehicle-mounted Cameras

Assuming planar motion for vehicle-mounted cameras is very beneficial as the visual estimation problems are simplified. Planar algorithms assume that the image plane is parallel to the gravity direction. This paper proposes two methods to correct camera images if this parallelity constraint does not hold. The first one utilizes that the ground is visible in the camera images, therefore its normal gives the gravity vector; the second method uses vanishing points to estimate the relative correction homography. The accuracy of the novel methods is tested on both synthetic and real data. It is demonstrated in real images of a vehicle-mounted camera that the methods work well in practice.