You will need an mpeg movie player to view the clips on this page. You should be able to find what you need here Images obtained from the scanning laser ophthalmoscope (SLO)
are obtained in raster order (fast scan left-to-right,
slow scan top-to-bottom). Significant image distortions are introduced
when the eye moves during the slow scan. These distortions
can be recovered by comparison with an undistorted template,
in order to infer the trajectory of the eye during the acquisition
of the image. Vertical motion produces vertical compression/expansion
of the image, horizontal motion produces horizontal shear, while
oblique motion produces combinations of the two. An estimate of the average eye motion can be obtained by
analysis of the cross correlation of the distorted image with
the template, illustrated in the following animated demonstration.View Deconvolution Movie(873K)
The display consists of four panels: the lower left panel
depicts a patch of retina, distorted by a simulated eye movement;
this image is band-pass filtered to accentuate the vascular features.
The filtered image is cross-correlated with an undistored template
(also filtered), and the cross correlation is shown in the upper
right panel. This cross correlation differs from the autocorrelation
of the template, in that the energy contributed from different parts
of the image are aligned differently with respect to each other.
This may be clearly visualized when the display is animated:
the angle of the simulated eye movement is rotated as the simulated
speed is slowly increased, producing larger and larger distortions.
The motions in the animated correlation image allow an observer
to pick out multiple motions (seen as transparent sheets) corresponding
to the relative motions of different featurs in the image.
The lower right panel shows the cross correlation after deconvolution
with the template autocorrelation. The velocity vector of the simulated
eye movement appears as a small bright line segment rotating about
the center of the image. The scanning laser opthalmoscope (SLO) is an instrument
producing high-resolution imagery of the fundus of the eye.
The application of image registration methods to digitized
SLO imagery allows post-hoc analysis of eye movement trajectories,
and allows combination of multiple images to reduce noise,
increase the area of retina imaged, and increase resolution.
The serial nature of the scanning process allows recovery
of high temporal resolution motion trajectories. View Template Movie(293K) Here is a Postscript file of the paper:Recovery of motion parameters from distortions in scanned images
Recovery of eye movement parameters from image distortions
Analysis of scanning-laser ophthalmoscope images