A computer-implemented method (100) is described. The method comprises receiving (102) imaging data obtained by an imaging system (204) of a subject (202) illuminated by first illumination (206a) in a first spectral band and second illumination (206b) in a second spectral band comprising different spectral content to the first spectral band. The second illumination incident on the subject is polarized. The imaging system is configured to obtain first imaging data within the first spectral band. The imaging system is further configured to obtain second imaging data within the second spectral band. The imaging system is further configured to admit the first and second illumination into the imaging system depending on a polarization state of reflected first and second illumination received by the imaging system after reflection from a surface of the subject. Information regarding specular reflection from the surface of the subject is determined by comparing the first and second imaging data.