R. Henry et Ar. Luxmoore, A PIPE-PROFILING ADAPTER FOR CCTV INSPECTION CAMERAS - DEVELOPMENT OFA PIPE-PROFILING INSTRUMENT, Measurement science & technology, 7(4), 1996, pp. 495-504
The principle of the optical section has been used to develop a profil
ing attachment for CCTV pipe inspection cameras. A light source, place
d in front of the camera, projects a ring of light onto the pipe wall,
which is then viewed by the camera. Any distortion in the pipe wall w
ill be made visible by the light ring. The CCTV image is digitized by
an electronic frame grabber and the light ring image is located by spe
cially developed pattern-matching software. The light ring shape is th
en analysed mathematically using a radial descriptor, which allows any
distortion to be represented in terms of a Fourier series. The device
has been tested in the laboratory and in the field, and has been used
to examine pipe degradation both in sewers and in water mains.