@techreport{WiebelVosHege2011, author = {Alexander Wiebel and Frans M. Vos and Hans-Christian Hege}, title = {Perception-Oriented Picking of Structures in Direct Volumetric Renderings}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {11-45}, language = {eng}, year = {2011} }