P. Göbel, A. N. Belbachir:
"Background Removal in Dental Panoramic X-ray Images by the A-Trous Multiresolution Transform";
in: "Proc. of the 17th IEEE European Conference on Circuit Theory and Design", IEEE, 2005, 331 - 334.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05936555