A method of transmitting image data in a safety sensor or in a safety system is provided, in which transmission errors are recognized in that meta information is added to the image data prior to the transmission and the meta information is checked after the transmission. The image data are here transmitted by an unsafe communication link, in particular a black channel, the meta information is prepended and/or appended to the image data and/or to the partial packets, and the meta information comprises a piece of information on the structure of the image data.