A fluorescence-based correlation mark is included in a printed document by encoding the correlation mark as phase shifts in the yellow halftone image only of a printed color document. Each of the light-emitting devices comprises a plurality of light sources for illuminating a target, wherein each of the light sources is configured to emit light within a predetermined color range. When the computer is manipulated for setting a mode through the image representing the mode setting device, the controller supplies an instruction signal for setting the selected mode to the camera, and the camera sets the mode in response to the instruction supplied from the controller. A portion of the time-based media may be selected for presentation by dragging or positioning at least one of the start graphical indicator and the stop graphical indicator along the graphical representation of the time line. Multiple magnets can be stacked together to form multi-pole-multi-throw relays.