A technique for processing patient-specific image data for computer assisted surgical navigation is described. A method realization of this technique comprises providing a database comprising multiple first data sets of two- or three-dimensional image data obtained by a medical imaging method. 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 of the particular patient 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 for each first shape data or first biometric data is calculated. A signal is generated based on the similarity score, wherein the signal triggers one of selection and de-selection of a first data set for computer assisted surgical navigation.
