View Full Version : 2D digitising with non-perpendicular camera

Peter Sinclair
01-21-2004, 03:31 PM
Dear BIOMCH-L members,

Does anyone have any experience with calibrating 2D images with
non-perpendicular camera views? We are using the APAS digitising system
which seems to do be doing a good job. With 18 co-planar calibration
control points spread through the field of view, the APAS calibration
routine accommodates the changing apparent image size to produce a
reasonable calibration. The system will measure a constant distance between
markers on a stick moved across the screen, but we haven't done more
rigorous tests at this stage.

We are only in the preliminary stage of testing the accuracy; needing to
measure (amongst other things) the accuracy's sensitivity to out of plane
movements. Are there theoretical reason's why the calibration of a
non-perpendicular camera position would be less reliable than the usual
perpendicular camera position?

Thanks very much for your assistance,

Peter Sinclair
Lecturer in Biomechanics
School of Exercise and Sport Science
The University of Sydney

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