A method is described for reconstructing the 3-dimensional coordinates
of
anatomical landmarks from
multiple video images. This method consists of 2 stages: (1) separate
reconstructions of landmark
coordinates visible in dorsal and ventral orientations using Direct Linear
Transformation (Abdel-Aziz &
Karara, 1972), and (2) least-squares alignment of the partial reconstructions
using landmarks present in
both. The repeatability of the overall reconstructions and of individual
landmarks were assessed by
performing multiple independent reconstructions of landmark coordinates
for
2 canid specimens. Results
indicate that the repeatability of interlandmark distances based on
stereophotogrammetric reconstructions
from standard-resolution video images is comparable to that of caliper
measurement, and slightly superior
to that of electronic 3-dimensional digitisation. At least 4 images should
be available per landmark for
optimal repeatability, but additional images allow only a slight increase
in repeatability.