Entwicklung und Evaluation eines 3D Object Retrieval Systems für digitalisierte Kulturobjekte

This thesis is about the construction, implementation and evaluation of a 3D object retrieval system for digitized cultural objects. After the integration and introduction to the used description method for 3D objects, called 3D Histogram of Oriented Gradients (abbr. 3D-HOG) [1][2] into the context of the current state of the art an explanation of each component of the retrieval system follows. In addition to the detailed description of the functional principle of the 3D-HOG descriptor a data basis was constructed. The data basis consists of cultural objects with high resolution polygon meshes. The evaluation contemplated different parameter choices and uses the measure of the R-precision [3] for early grading. By using the block normalization, the cell quantity and the size of the gradient field, the three most important parameters of 3D-HOG, it was possible to improve the R-precision from 0.799 to 0.888. Furthermore it was shown that the resolution of the polygon meshes is a matter of secondary importance as the resolution barely influences the results of the chosen description method