A method for automatically modifying the rendering of an image based on an analysis of pixel values within a selected region of interest. Various other apparatuses, systems, methods, etc. The authorization zone may be formed using as least three LF antennas. The chip contact pads may have a distribution such that an area portion of the active chip surface is available for attaching a thermally conductive plate; this plate has a thickness compatible with the thickness of the conductive pad layer. Guide grooves are longitudinally provided on either longitudinal frames of the bed body or those of the outer frame at four corners thereof, and guide rollers which engage in the guide grooves are fixed to the other longitudinal frames of the outer frame or those of the bed body at the four corners.