Inverting input scanner vibration errors

Images scanned in the presence of mechanical vibrations are subject to artifacts such as brightness fluctuation and geometric warping. The goal of this work is to develop an algorithm to invert these distortions and produce an output digital image consistent with a scanner operating under ideal uniform motion conditions. The image restoration algorithm described in this paper applies to typical office scanners that employ a moving linear sensor array (LSA) or moving optics. The velocity of the components is generally not constant in time. Dynamic errors are introduced by gears, timing belts, motors, and structural vibrations. In this work, we make use of the instantaneous LSA velocity to reconstruct an underlying piecewise constant or piecewise linear model of the image irradiance function. The control points for the underlying model are obtained by solving a system of equations derived to relate the observed area samples with the instantaneous LSA velocity and a spatially-varying sampling kernel. An efficient solution exists for the narrow band diagonal matrix that results. The control points computed with this method fully define the underlying irradiance function. That function is then suitable for resampling under ideal scanning conditions to produce a restored image