DETECTOR FOR IDENTIFYING AT LEAST ONE MATERIAL PROPERTY

Abstract

A detector (110) for identifying at least one material property m is proposed. The detector (110) comprises at least one sensor element (116) comprising a matrix (118) of optical sensors (120), the optical sensors (120) each having a light-sensitive area (122). The sensor element (116) is configured for recording at least one reflection image of a light beam originating from at least one object (112). The detector (110) comprises at least one evaluation device (132) configured for determining the material property by evaluation of at least one beam profile of the reflection image. The evaluation device (132) is configured for determining at least one distance feature φ1z by applying at least one distance dependent image filter Φ1 to the reflection image. The distance dependent image filter is at least one filter selected from the group consisting of: a depth- from-photon-ratio filter; a depth-from-defocus filter; or a linear combination thereof or a further distance dependent image filter Φ1other which correlates to the depth-from-photon-ratio filter and / or the depth-from-defocus filter or a linear combination thereof by |ρΦ1other,Φz|≥0.40 with Φz being one of the depth-from-photon-ratio filter or the depth-from-defocus filter or a linear combination thereof. The evaluation device (132) is configured for determining at least one material feature φ2m by applying at least one material dependent image filter Φ2 to the reflection image. The material dependent image filter is at least one filter selected from the group consisting of: a luminance filter; a spot shape filter; a squared norm gradient; a standard deviation; a smoothness filter such as a Gaussian filter or median filter; a grey-level-occurrence-based contrast filter; a grey-level-occurrence-based energy filter; a grey-level-occurrence-based homogeneity filter; a grey-level-occurrence-based dissimilarity filter; a Law's energy filter; a threshold area filter; or a linear combination thereof; or a further material dependent image filter Φ2other which correlates to one or more of the luminance filter, the spot shape filter, the squared norm gradient, the standard deviation, the smoothness filter, the grey-level-occurrence-based energy filter, the grey-level-occurrence-based homogeneity filter, the grey-level-occurrence-based dissimilarity filter, the Law's energy filter, or the threshold area filter, or a linear combination thereof, by |ρΦ2other,Φm |≥0.40 with Φm being one of the luminance filter, the spot shape filter, the squared norm gradient, the standard deviation, the smoothness filter, the grey-level-occurrence-based energy filter, the grey-level-occurrence-based homogeneity filter, the grey-level-occurrence- based dissimilarity filter, the Law's energy filter, or the threshold area filter, or a linear combination thereof. The evaluation device (132) is configured for determining a longitudinal coordinate z and the material property m by evaluating the distance feature φ1z and the material feature φ2m.