Using
projective gemotery it can be
shown that the deviation of the blur kernel as a result of only
z-translation lies within a pixel at any point in the image until,

tz > d / (x0-1)

where tz
is the amount of
z-translation, d
is the scene
depth and x0
is the
x-coordinate of the image center. For a 6MP camera (x0
~= 1500), the allowed
z-translation is around 4mm for a depth of 6m. Typical camera shake
motion shown in the anonymous work cited in
our paper lies within this order
of operating range. The following
graph shows the plot of the allowed z-translation for different values
of depth for a 6MP camera.

In our paper, we work with 768X512
sized images for which the operating
range is almost the double of that shown above.