A method of masking part of an image of a scene captured by a camera monitoring the scene, comprising the steps of mounting a light source such that it illuminates a part of the scene with light having a predefined spectral content and a spatial verification pattern, capturing a first type of image of the scene by a first sensor sensitive to the predefined spectral content, capturing a second type of image of the scene by a second sensor insensitive to the predefined spectral content segmenting the first type of image, based on the predefined spectral content, to find a candidate image region, detecting a spatial pattern in the candidate image region, comparing a characteristic of the detected spatial pattern to a corresponding characteristic of the predefined spatial verification pattern, and, if the characteristics match, identifying the candidate image region as a verified image region corresponding to the marked part of the scene, finding an image region, in the second type of image, which corresponds to the verified image region in the first type of image, providing a privacy mask, in the second type of image, for the image region corresponding to the verified image region, or providing a privacy mask, in the second type of image, for the remaining part of the second type of image, outside the image region corresponding to the verified image region further comprising the steps of modulating the spatial verification pattern between at least a first and a second spatial verification pattern according to a temporal modulation sequence, and with a respective one of the first and the second spatial verification pattern, in accordance with the temporal modulation sequence, repeating the steps of capturing, segmenting, detecting and comparing. mounting a light source such that it illuminates a part of the scene with light having a predefined spectral content and a spatial verification pattern, capturing a first type of image of the scene by a first sensor sensitive to the predefined spectral content, capturing a second type of image of the scene by a second sensor insensitive to the predefined spectral content segmenting the first type of image, based on the predefined spectral content, to find a candidate image region, detecting a spatial pattern in the candidate image region, comparing a characteristic of the detected spatial pattern to a corresponding characteristic of the predefined spatial verification pattern, and, if the characteristics match, identifying the candidate image region as a verified image region corresponding to the marked part of the scene, finding an image region, in the second type of image, which corresponds to the verified image region in the first type of image, providing a privacy mask, in the second type of image, for the image region corresponding to the verified image region, or providing a privacy mask, in the second type of image, for the remaining part of the second type of image, outside the image region corresponding to the verified image region identifying the candidate image region as a verified image region corresponding to the marked part of the scene, finding an image region, in the second type of image, which corresponds to the verified image region in the first type of image, providing a privacy mask, in the second type of image, for the image region corresponding to the verified image region, or providing a privacy mask, in the second type of image, for the remaining part of the second type of image, outside the image region corresponding to the verified image region further comprising the steps of modulating the spatial verification pattern between at least a first and a second spatial verification pattern according to a temporal modulation sequence, and with a respective one of the first and the second spatial verification pattern, in accordance with the temporal modulation sequence, repeating the steps of capturing, segmenting, detecting and comparing.