A. Stern et al., Enhanced-resolution image restoration from a sequence of low-frequency vibrated images by use of convex projections, APPL OPTICS, 40(26), 2001, pp. 4706-4715
An algorithm to increase the spatial resolution of digital video sequences
captured with a camera that is subject to mechanical vibration is developed
. The blur caused by vibration of the camera is often the primary cause for
image degradation. We address the degradation caused by low-frequency vibr
ations (vibrations for which the exposure time is less than the vibration p
eriod). The blur caused by low-frequency vibrations differs from other type
s by having a random shape and displacement. The different displacement of
each frame makes the approach used in superresolution (SR) algorithms suita
ble for resolution enhancement. However, SR algorithms that were developed
for general types of blur should be adapted to the specific characteristics
of low-frequency vibration blur. We use the method of projection onto conv
ex sets together with a motion estimation method specially adapted to low-f
requency vibration blur characteristics. We also show that the random blur
characterizing low-frequency vibration requires selection of the frames pri
or to processing. The restoration performance as well as the frame selectio
n criteria is dependent mainly on the motion estimation precision. (C) 2001
Optical Society of America.