In order to increase safety, a computer-implemented method is proposed for determining the position of a lift cabin in a lift shaft with the aid of a coding device, in which method a section of a code band and/or of the bearing device is/are recorded with an optical detection device as a pixel image consisting of pixels, a reference marking analysis is carried out, the pixel image is processed, in particular is assigned to a detection grid, pixels of the pixel image are preferably combined with the aid of their color and/or position in order to be able to read out the barcode and/or 2D code of the marking, the barcode and/or 2D code is converted to a binary code, the binary code is decoded by means of an algorithm and is converted into a position indication and/or into information as to whether a bearing device has been detected.