Investigation of the compatibility of X-CT measurement data to surface topography analysis

In recent years X-CT metrology becomes more popular as a promising geometrical measurement technique. In comparison to traditional tactile and optical metrology techniques, X-CT has the unique advantage: it is a non-destructive method which can measure the complete internal and external geometry without constraint. Although X-CT has a limitation on the measurement of surface texture due to limited resolution, it is qualified for that of most of additive processed surfaces, which are featured by high roughness surface texture comprising a number of topographical features, such as bumps, step markings and surface pores.
The X-CT generated data structures for the object surface, either point cloud or triangular mesh, differ from the grid structure of traditional methods. To enable X-CT data structures compatible with surface topography, two strategies are investigated: One is to interpolate scattered points into grid structure. The other one is to perform surface analysis on triangular mesh. The pros and cons of two different routes are discussed and compared. The application of the surface analysis techniques e.g. filtration, segmentation, parameterisation etc. following two different strategies are illustrated respectively.