A technique for processing patient-specific image data for computer assisted surgical navigation. A database is provided including multiple first data sets of two- or three-dimensional image data. Each first data set is representative of first shape data or first biometric data of a skin surface of at least one patient. The method further comprises obtaining, by an optical camera system, a second data set of two- or three-dimensional image data of a skin surface of a particular patient and deriving second shape data or second biometric data of the skin surface from the second data set. By comparing the second shape data or second biometric data with the first shape data or the first biometric data of one or more first data sets, a similarity score is calculated. A signal generated based on the similarity score triggers one of selection and de-selection of a first data set.
