The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008
the mural firstly, and then we marked the diseases using 3D
models and 3D orthophotoes of the murals.
Figure 7(a) is the disease marks that the professionals drew in
2D panoramic of the mural. It shows type and distribution of
mural diseases, but it cannot give true position and true size of
mural diseases. Determining true position and true size of mural
diseases must depend on 3D model and 3D orthophoto, just like
Figure 7(b)-7(d).
(b)
(c) (d)
Figure 7. Diseases marking
5. CONCLUSIONS
Mural survey is a complex task, and we have proposed a system
for investigation on mural diseases in 3D space using laser
scanning and photogrammetry: range image and digital image
recording the information of murals. Range images constrain
geometry and digital images constrain colour texture.
In trying to acquire and post-process laser data and image data,
we had to force many difficulties. We discussed the methods of
post-processing range data and image data, these methods can
be applied to other applications. We presented a method of
mapping the images from a hand-held digital camera onto 3D
model, and this method is very useful to integrating laser
scanning with digital photogrammetry.
We verified that integrating laser scanning with digital
photogrammetry is one of the important means for mural survey
by the investigation on mural diseases of Jokhang Temple.
In particular, there were several disappointments. Some images
we captured could be used because of image quality questions,
and the bigger holes because of occlusions and self occlusions