  Cameras with rolling shutters are becoming more common as low-power, low-cost
CMOS sensors are being used more frequently in cameras. The rolling shutter
means that not all scanlines are exposed over the same time interval. The
effects of a rolling shutter are noticeable when either the camera or objects
in the scene are moving and can lead to systematic biases in projection
estimation. We develop a general projection equation for a rolling shutter
camera and show how it is affected by different types of camera motion. In the
case of fronto-parallel motion, we show how that camera can be modeled as an
X-slit camera. We also develop approximate projection equations for a non-zero
angular velocity about the optical axis and approximate the projection equation
for a constant velocity screw motion. We demonstrate how the rolling shutter
effects the projective geometry of the camera and in turn the
structure-from-motion.
