Stereoscopic Parallax

1. Stereoscopic Parallax
Dr. Divya Priya B
Assistant Professor (Senior)
School of Civil Engineering

9. Eye base (6-7cm)

11. Human vision
3-D stereoptic viewing of
the Earth’s surface is
possible using
overlapping pairs of
vertical stereo aerial
photographs

18. In the left image the Space Needle in Seattle was located close
to the principal point so there is minimal displacement. In the
right image the Space Needle is located further away from the
principal point causing it the "lean" away from the center.

36. • Orthophotographs or orthoimagery are aerial photographs
that have been geometrically corrected for topographic
relief, lens distortion and camera tilt.
• This means that the distortions have been removed and
scale is uniform through out the image. This allows for the
accurate direct measurement of distances, angles, and
areas.
• Orthophotos combine the visual attributes of an aerial
photograph with the spatial accuracy and reliability of a
map. The process of creating orthophotos is known
as orthorectification.
• The orthorectification process requires two main things:
first, accurate information about the sensor geometry,
which includes information about the sensor location and
orientation for the image. The second is an accurate terrain
or elevation model.

37. The below image shows the same area in an unrectified image on the left and an
orthorectified image on the right. Notice the road that passes through the mountains in
the center of the image appears to be crooked in the unrectified aerial photograph. This
is due to the terrain features. The image on the right is a rectified orthophoto and the
road appears planimetrically correct.