TUNNEL WALL SURFACE PHOTOGRAPHING METHOD, TUNNEL WALL SURFACE PHOTOGRAPHING DEVICE AND TUNNEL BORING MACHINE

PROBLEM TO BE SOLVED: To obtain an undistorted development image of even a tunnel of noncircular cross section. SOLUTION: An omnidirectional photographing lens 24 guides light taken in at a fixed angle of visibility α from a tunnel wall surface 21, to a camera 25. The camera 25 obtains a concentric omnidirectional image, displays it on a monitor 32 and stores it in an image storage part 33. When the omnidirectional photographing lens 24 is shifted from a tunnel axis and one image pickup range far from the tunnel wall surface 21 becomes larger than the other close image pick-up range, an image processing part 31 deletes the extra image, larger than the other image pickup range, out of one image pickup range in the units of picture elements on the basis of digital image data stored in the image storage part 33 and copies the remaining image in the units of picture elements to enlarge it into an image with the same number of picture elements as the other image pickup range, thus obtaining the concentric omnidirectional image with the tunnel wall surface of the same width photographed in all directions.